(2024) 22:349
Duus et al. BMC Medicine
https://doi.org/10.1186/s12916-024-03561-2

BMC Medicine

RESEARCH

Open Access

Implementation of health‑promoting
retail initiatives in the Healthier Choices
in Supermarkets Study—qualitative
perspectives from a feasibility study
Katrine Sidenius Duus1* , Tine Tjørnhøj‑Thomsen1   and Rikke Fredenslund Krølner1   

Abstract
Background Improving food environments like supermarkets has the potential to affect customers’ health positively.
Scholars suggest researchers and retailers collaborate closely on implementing and testing such health-promotinginterventions, but knowledge of the implementation of such interventions is limited. We explore the implementationof four health-promoting food retail initiatives selected and developed by a partnership between a research institu‑
tion, a large retail group, and a non-governmental organisation.
Methods The four initiatives included downsizing of bags for pick’n’ mix sweets and soda bottles at the check-out
registers, shelf tags promoting healthier breakfast cereal options, and replacing a complimentary bun with a banana
offered to children. The initiatives were implemented for 6 weeks (or longer if the store manager allowed it) in one
store in Copenhagen, Denmark. Data were collected through observations, informal interviews with customers,
and semi-structured interviews with retailers. We conducted a thematic analysis of transcripts and field notes inspiredby process evaluation concepts and included quantitative summaries of selected data.
Results Two out of four initiatives were not implemented as intended. The implementation was delayed due
to delivery issues, which also resulted in soda bottles not being downsized as intended. The maintenance of the shelftags decreased over time. Retailers expressed different levels of acceptability towards the initiatives, with a preference
for the complimentary banana for children. This was also the only initiative noticed by customers with both positive
and negative responses. Barriers and facilitators of implementation fell into three themes: Health is not the number
one priority, general capacity of retailers, and influence of customers and other stakeholders on store operation.
Conclusions The retailers’ interests, priorities, and general capacity influenced the initiative implementation. Retailers’
acceptability of the initiatives was mixed despite their involvement in the pre-intervention phase. Our study also sug‑gests that customer responses towards health-promoting initiatives, as well as cooperation with suppliers and manu‑
facturers in the development phase, may be determining to successful implementation. Future studies should explore
strategies to facilitate implementation, which can be applied prior to and during the intervention.
Keywords Implementation, Qualitative research, Health promotion, Supermarkets, Involvement, Intervention*Correspondence:
Katrine Sidenius Duus
ksdu@sdu.dk
Full list of author information is available at the end of the article© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to theoriginal author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images orother third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line
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regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of thislicence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecom‑mons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Duus et al. BMC Medicine(2024) 22:349

Background
What we eat affects our health and well-being [1]. Dietis associated with obesity, cancers [2], and mental wellbeing [3], and a healthy diet has been associated withlower all-cause mortality [4]. One important factor in
improving diet is to create a food environment that supports a healthy diet [5, 6]. In modern societies, such as
Denmark, supermarkets are the main source of food [7].
Supermarkets therefore hold a significant influence on
what food we buy and potentially also eat [7–9]. Studies
report associations between the concentration of supermarkets and overweight and obesity in the neighbourhood [10] and between the healthfulness of supermarkets
and people’s diets [11, 12]. Moreover, unhealthy food andbeverage products are promoted more often than healthy
products and beverages in, for example, supermarkets[9, 13, 14]. This indicates a need to explore how and if it
is possible to implement health promotion initiatives insupermarkets and whether customers respond to suchinitiatives as intended.
Studies show that health-promoting interventions insupermarkets can affect customers to purchase more
healthy products [7, 9, 15–17]. Reviews and a metaanalysis have concluded that the most effective initiative in supermarket settings is price changes—theevidence points to the positive effects of reduced prices
to increase the purchase of healthier products, especially fruit and vegetables [7, 17]. Even though pricereductions seem to be effective, they seem more challenging to implement due to retailers’ drive for profit
and low preference for financing such price cuts [7, 18].
There is some evidence that nudges in terms of product information and positioning, as well as altering thenumber of available products, can impact what products are being purchased [15, 16]. However, the qualityof this evidence is low. Overall, most of the studies thathave explored the effect of interventions in supermarkets have been conducted in the USA and other highincome countries [15, 16], in controlled settings, orapplied a weak study design, such as non-randomised
studies [16, 17]. To our knowledge, only a few studies
have been conducted in Denmark [19–25]. These studies represent different designs and types of interventions: reformulation of private-label products to reduce
calorie content [24], informational claims to promote
low-salt foods [23], nudges via signs to promote salesof fruit and vegetables [22], positioning (shelf-space
management) of dairy products [20], replacement ofsugar confectionery with fruit and healthy snacks at
the checkout [19], discount on fruit and vegetables
combined with space management [25] and structuralchanges in supermarkets and education of supermarket
employees as part of a multicomponent intervention

Page 2 of 18[21] (the three latter studies are reporting from thesame project). All but one study [23] found an effectof the applied intervention strategies, although mostly
small or modest. This calls for more studies in reallife settings and investigations of why some interventions have the desired effect while others do not. Lackof effect may be explained by 1) customers not noticing
or finding the initiatives relevant [19, 23], 2) customers buying other products instead of or additionally topromoted intervention products [20, 24], 3) the shelforganising effect [20], or 4) theory fail in regards tocustomer behaviour [22].
Several studies have explored facilitators and barriers
to the implementation of health-promoting interventions
in supermarkets. Reviews show that implementation is
supported if the retailer is receptive to innovation, feels
responsible for community health, and receives financial
support or subsidies [26]. Furthermore, implementation is supported if the intervention provides the retailers with knowledge of health promotion and businessskills [26, 27]. Other facilitators include compatibility
with context and customers’ needs, positive customer
responses to the initiative, the prospect of improved
public image, establishment of partnerships, low retailer
effort requirements, and increased profit or sales [26, 27].
Health-promoting interventions in supermarkets are hindered by high customer demand for unhealthy products
and lower demand for healthy products, constraints ofstore infrastructure, challenges in product supply, highstaff turnover, and lack of time [26, 27]. Other barriers
are doubt regarding changing customers’ behaviour, poor
communication between collaborators [26], high runningcosts, and risk of spoilage [26, 27].
Middle et al. [26] conclude that the underlying mechanism of barriers and facilitators of implementation is the(mis)alignment of retailers’ and intervention researchers’ interests. The authors, therefore, suggest a close collaboration between intervention researchers and retailers
to work towards an alignment of interests and resolving
or avoiding misalignment, which is supported by Gupta
et al. [27]. However, knowledge of how such collaborative
efforts affect the implementation of healthy food retailinterventions is warranted.
The aim of this study is to explore the implementation,
acceptability, and feasibility of four different health-promoting food retail initiatives to increase customers’ purchase of healthy food and beverages, which were selected
and developed together with food retailers: 1) Promotion of healthier breakfast cereals and products using
shelf tags, 2) downsizing of sodas sold at the checkout
desks, 3) downsizing of bags for the pick’n’ mix sweets, 4)
replacement of a complimentary bun for children with abanana. The study has three research objectives:

Duus et al. BMC Medicine(2024) 22:349(I) To document the implementation and sustainmentof the initiatives over time(II) To explore the retailers’ and customers’ responses
to and acceptability of the initiatives(III) To investigate barriers and facilitators of implementation and sustainment of the initiatives.

Methods
Setting and the initiatives

This study was conducted in Denmark during 2020 and
2021, 2 years that involved two major societal events, firstthe coronavirus disease pandemic and later the start of
the Russia-Ukraine war. Both events heavily influenced
the circumstances of everyday life including opportunities for conducting research and running businesses. The
specific influences on this study will be unfolded later inthe findings and discussion sections.
In this study, we collaborated with the retailer SallingGroup, which holds 34.2% of the market share of grocery
retailers in Denmark [28]. Salling Group is owned by the
Salling Foundations and has no shareholders—all profits go to reinvestment in the business and donations tosports (amateur and professional), charity, education, andresearch. Salling Group owns three national supermarket chains: føtex, Netto and Bilka, alongside other businesses. For the feasibility test, we collaborated with føtex,which owns over 100 stores all over Denmark, including 23 stores called føtex food. føtex (except føtex food)offers both groceries and many different non-food products (e.g. textiles, cosmetics, toys, electronics, and homeaccessories).
The initiatives were selected and developed by a partnership, including a group of researchers at the National
Institute of Public Health, University of Southern Denmark, consultants from the Danish Cancer Society, andemployees at the Corporate Social Responsibility (CSR)
department in Salling Group, the marketing departmentat føtex, and two store managers (hereafter referred collectively to as ‘the retailers’) over approximately 2 years.
The process involved in-person meetings, desk research(the use of existing material [29]), visits to the test store,
and a prototype test of three suggested initiatives. The
researchers initiated the collaboration and were responsible for designing the research study and data collection
and analyses. The retailers hosted the site of the feasibility test, contributed to the selection and development ofinitiatives and co-managed the practical part of the study.
The Danish Cancer Society was recruited by the research
project to develop the initiatives. A detailed descriptionof the collaboration and development process is reported
elsewhere (Duus et al. unpublished).

Page 3 of 18

The feasibility test ended up including four initiatives:
1) Promotion of healthier breakfast cereals and products using shelf tags, 2) downsizing of soda sold at thecheckout desks, 3) downsizing of bags for the pick’n’
mix sweets, 4) replacement of a complimentary bun forchildren with a banana (suggested by the retailers). The
initiatives were based on a compromise between thewillingness of the retailers and the interest and ideasof the remaining partners rather than on what the literature suggests are the most effective strategies (Duuset al. unpublished). Detailed descriptions of the initiatives
and the rationale behind them are found in Table 1.
The prototype test showed that 1) It was important tohave a sign informing the customers about the initiative that offered a free banana to children instead of theusual free bun to create a better understanding of thechanged offer; 2) Promotional shelf tags needed weekly
maintenance as some would fall off; 3) It was difficult tosustain an initiative promoting ready-to-serve salads andready-to-cook vegetables next to different fresh meats, as
it met resistance among the staff due to being an additional task and led to more product waste (Customers did
not expect to find these products next to the meat andtherefore might not notice them). The learnings from theprototype test led to modifications of the implementation
plan and the discard of the latter initiative. The prototype
test also made us aware of how quickly the selection offood offered and the layout of the store changed overtime, which the researcher, therefore, paid extra attention to during subsequent data collection. Moreover, theresearcher made sure to update the list of products thatshould have a shelf tag a few weeks before the implementation to include new products offered.
The føtex marketing department developed a script to
inform the staff at the test store about the feasibility test,
explaining and showing each initiative and the aim of thestudy overall. This was sent to the store manager after
being reviewed by the researchers. The store manager
was responsible for informing all relevant staff about theimplementation and maintenance of the initiatives. The
føtex marketing department also made sure to inform therelevant suppliers. Employees at the test store and brandstaff from a brewery (who stock the coolers at the checkout desks) implemented the initiatives in the store. The
research group did not correct or maintain the initiatives in the store after they were launched; however, theresearchers monitored it and reported back to the retailers, either at meetings or by email.
Overall study design

The four initiatives were implemented in the test store
for 6 weeks (or longer if the store manager allowed it)
starting in September 2021. A føtex store in centralReplacement of the complementary bun for children
with a banana

Fruit

The banana is thought of as a possibly healthier alternative
to the bun (by the retailer). The emphasis on customer careis greater than health

The amount of sugar, fat and energy from candy in the dietis reduced

The amount of sugar, salt, and fat from cereal productsin the diet would be reduced, and the amount of wholegrain
would increase

Customers will consume fewer sodas, which will decrease
their sugar and energy intake from sugar-sweetened variants
and reduce other potential health risks of consuming bever‑ages with sugar or artificial sweeteners (e.g. dental erosions)

Assumptions of health behaviour

Both variants were included in the initiative to secure adherence to the downsizing working mechanism. Different sizes would increase the chance of substitution, e.g. choosing the larger variant if it was presented next
to the smaller variant*

A smaller, narrower bag (that customers would not notice),that can contain fewer sweets and make the amountin the bag seem like more than the original bag, will leadcustomers to buy fewer sweets

Downsizing of the pick’n’ mix bags for sweets by making
them narrower

Candy

Promote free fruit as a customer care initiative to accommo‑
date those wanting a healthier alternative

The use of familiar labelling to customers will promote salesof healthier cereal products and inspire customers to buy
a healthier alternative

Downsizing of Coca-Cola original and Coca-Cola zero bottles Customers will continue to buy sodas from the cool‑ers at the checkout desk and the bakery (impulse buys),from 500 to 375 ml in the coolers at the checkout desks
and then naturally get a smaller volume due to the smallerand the cooler at the ­bakery*sized bottle (that customers might not notice)

Assumptions of customer behaviour

Breakfast Highlighting breakfast cereals by adding a shelf trailer
on the price tag with the front of the package labelling‘Keyhole’ and/or ‘Whole grain logo’ which indicate prod‑
ucts with a high content of wholegrain and a low content
of sugar, salt, and fat

Sodas

The area The initiative

Table 1 The four initiatives included in the Healthier Choices in Supermarkets Study

Duus et al. BMC Medicine(2024) 22:349
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Duus et al. BMC Medicine(2024) 22:349

Copenhagen (the capital city of Denmark) was chosen
as the test store. This decision was made for pragmatic
reasons, as the research institute is based in Copenhagen,and based on Salling Group’s decision as it offered their
new store layout, which all stores were in the process of
being converted to (it was the same store as where theprototype test was conducted).
We designed a qualitative study involving participant
observations and interviews to evaluate the feasibilityof the initiatives. The methods were designed to explore
the partnership and collaboration (the aim of anotherpublication [Duus et al. Unpublished]), as well as theimplementation of the initiatives [30]. In the design ofthis study, we were inspired by McGill et al.’s (2020) twophase framework of qualitative process evaluation froma complex systems perspective. This framework suggests
an evaluation that looks at changes over time, startingwith phase 1, the static system description and hypothesis generation about how the system might change when
the intervention is introduced, followed by phase 2, an
adaptive evaluation approach to the system undergoingchange which follows emerging findings [31].
Data collection
In‑store observations

During October and November 2020, we mapped thestore layout and customer flow in the test store as partof the static system description. Over 3 weeks, threeresearch assistants performed 12 participant observations of 1005 min in total. The observations followed an
observation guide which covered 1) the physical setting(e.g. the layout, placement of products, signs, and pictures); 2) the people (e.g. who are the customers? Are
people shopping alone or together with others? How dothey move around the store? What are the staff doing?)and 3) short interviews with customers (if possible) about
their shopping at the particular store, and their thoughts
about the layout of the store. The research teams’ accessto the store was approved by the store manager, andresearch assistants wore a key chain with a sign showing
their name and affiliation during the observations. During this data collection period, it was made mandatory touse face masks in supermarkets due to the coronavirus

Page 5 of 18

disease pandemic. As the implementation was delayed
to approximately 1 year after this static description wascompleted, one participant observation in the test store
was performed at the end of August 2021, just before initiative implementation, to document any major changes
in the store layout and selection. Key lessons from theseobservations about the test supermarket and customers’ behaviour in the store included knowledge on 1) theroute around the store, 2) the different times spent at
the store, 3) interactions with objects (e.g. products andphones), 4) interactions with children, 5) behaviour of thestaff, and 6) sensory impression (Additional file 1). Theselessons informed our following data generation andassisted in contextualising our analysis.
The first author monitored the implementation process through participant observations of status meetings(n = 2) and correspondence via email and phone with thestore manager and the contact person at føtex. In-store
participant observations were conducted during andafter the feasibility test period, September 2021–May
2022 (n = 25 ~ 1795 min in total; see Additional file 2).
These observations focused on documenting the presence of the initiatives as well as customers’ and staff ’s
responses to the initiatives. Access to the store was once
again approved by the store manager, and the researcher
wore a key chain. During the participant observations
in-store, we conducted informal interviews with customers (see Additional file 2 for examples of questions),
which lasted a maximum of 5 min each. The first author
would approach people and ask if they were interested
in answering a brief question. She introduced herself
by her first name, where she worked and explained she
was doing a research project about shopping patterns.
The participant observations were documented by taking notes and photos. Handwritten notes were digitalised and written down at the first chance after leaving thestore.
Qualitative interviews

Between November 2021 and February 2023, the firstauthor conducted four semi-structured interviews withretailers (n = 3) who had been involved in the study(Table 2) to explore their views on the initiatives and theTable 2 Interviews
Informant

Period and type of involvement

Time and place

Duration

føtex representative (A)Development of the initiatives and decision-making
at the executive level, 2019–2021

February 2023, telephone

40 minføtex representative (B)Primary contact at group/chain level and co-manag‑
ing implementation, 2021

November 2021, online

50 minStore manager

Primary contact in the test store, 2021

February 2022, online
May 2022, online

55 min55 minDuus et al. BMC Medicine(2024) 22:349

implementation process. Interview guides were used in
all interviews alongside different prompts (e.g. timelinesand documents). Interview guides were tailored to eachparticipant’s specific role and involvement in the development and implementation of the initiatives. Besides
questions related to the initiatives and the implementation effort, the guides included questions about the
informants’ background and motivation for the project(personally and professionally), their view on their roleand scope for action (individually and organisationally)
and their perception of the collaboration with the otherorganisations. After the participants’ consent was given
verbally right before the interview, the interviews wererecorded and later transcribed verbatim.
Analyses

To explore the level of implementation (research objective I), all field notes and photos taken during and after
the feasibility test were reviewed to assess whether the
initiatives were present and to what degree (e.g. x out of x
possible tags).
To explore the perception of the initiatives among
employees and customers (research objective II) andidentify barriers and facilitators for implementing theinitiatives (research objective III), we followed a thematic
analysis inspired by Braun and Clarke [32]. Firstly, fieldnotes and interview transcripts were read thoroughly
and openly coded, by writing keywords in the margin of
the material, with a focus on the two research objectives.
After initial coding, the codes were summarised into
broader themes, by writing them into a document withshort descriptions and revised according to data excerpts
and the full empirical material. The themes drew on theprocess evaluation concepts: acceptability, responsiveness [30], motivation, general capacity to implement [33]and commercial viability [34]. Lastly, the themes werenamed, and the final analysis was written up.

Findings
We have structured the presentation of study findings
as follows: Firstly, we present the implementation of theinitiatives overall. Secondly, we present the implementation of each initiative, customers’ responses to them, andthe retailers’ perspectives. Lastly, we present the overall facilitators and barriers to the implementation of theinitiatives.
Implementation of the initiatives

The implementation of the initiatives was challenged.
Firstly, we found that not all the preparations for the
implementation were finished in time for the scheduled day. On the scheduled day, the retailer decided
to push back the implementation by 1 week. The main

Page 6 of 18

reasons were that there had been some misunderstandings around the ordering of the smaller sodas. It was
informed that the smaller soda would be a 330 ml caninstead of the 375 ml bottle at the price of DKK 10.00(~ 1.3 euros). The 500 ml bottle usually sold at the coolers
cost DKK 16.00 (~ 2.2 euros). The Danish Cancer Society
and the research group had two concerns about this: 1)
the use of a can instead of a bottle would make the interpretation of the results very difficult, as the bottle and thecan have two different functions to the customer—with
the can, the product would be consumed all at once,
whereas the bottle with the screw lid could be saved forlater after it had been open; 2) the price was too low—theprice per litre would be lower on the smaller sodas thanit had been on those replaced. No changes were madedespite these concerns.
Secondly, just days before the implementation, theretailers informed the other partners that they would
stick with cans for the test of smaller-sized sodas andthat they would now be 250 ml. They acknowledged thatboth the size and the packing were not optimal but thatthe optimal 375 ml in a bottle was just not possible. Additionally, they informed the researchers that they could
no longer find the new bags produced for the pick’n’mix
sweet display.
These challenges led to a delay of the implementationof the initiatives by 1 week, but also a staggered implementation, where the initiatives were implemented when
ready (the soda initiative 2 weeks later and the bags for
pick’n’ mix sweets 8 weeks later). The retailers agreed topush back the end day correspondingly, upholding the
6 weeks of implementation. Table 3 shows an overview
of the implementation of the four initiatives according to
the day and week of the feasibility test period.
Smaller product sizes of sodas at the checkout desk

As seen from Table 3, we did observe the implementation of a smaller product size of the targeted sodas in allcoolers, besides the one at the bakery, in the week leading up to the agreed date. We hereafter observed a full
implementation of 250 ml cans during the first 2 weeks
of implementation. During the third week and the beginning of the fourth week, we observed a mix of 250 and
330 ml cans or only 330 ml cans. The store manager
explained that this was probably due to non-deliveringfrom the supplier. At the end of the fourth week andfor the last 2 weeks, we observed a full implementation of 250 ml cans. As the targeted size of the initiative
was a 375 ml bottle, the initiative was not implemented
as intended. After the 6-week feasibility test period, we
observed that the smaller 250 ml cans were available inall coolers for at least eight more weeks. As expected, thepresentation of the coolers fluctuated over the period. On

Duus et al. BMC Medicine(2024) 22:349

Page 7 of 18

Table 3 Implementation of the four initiatives according to the day and week of the feasibility test period
Day and week of feasibility test period

Sodas at the coolers

Tags at the cerealsn (%), N = 31

BananasBags for pick’n’ mix sweets

Week 11

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)
1 misplaced

Bananas present
Sign present

N/A

3

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)1 hidden
1 misplaced

Bananas present N/A
Sign not present

6

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)
1 misplaced

Bananas present
Sign present

N/A

8

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)
1 misplaced

N/A

N/A

11

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)
1 misplaced

Bananas present
Sign present

N/A

13

Only 250 ml cans at thecheckout desk
Only 500 ml bottles at the
bakery28 (90%)
1 misplaced

Bananas present
Sign present

N/A

15 (Official first day
with sodas)

Only 250 ml cans in allcoolers and fridges

28 (90%)
1 misplaced

Bananas present
Sign present

N/A

21

Only 250 ml cans in allcoolers and fridges

28 (90%)
1 misplaced
1 tagged cereal sold out

Bananas present
Sign present

N/A

Week 428

Only 250 ml cans in allcoolers and fridges

27 (87%)
1 misplaced

Bananas present
Sign present

N/A

Week 530

Both 250 ml and 330 ml
cans in all coolers
and fridges

26 (84%)Bananas present
1 misplaced
Sign present
1 tagged product sold out

N/A

33

Only 330 ml cans
26 (84%)Bananas present
at the check-out desk. Both 1 misplaced
Sign present
250 ml and 330 ml cans
1 tagged product sold out
at the bakery

N/A

36

250 ml cans in all coolers
and fridges. A few 330 ml
cans at the checkout desks

24 (77%)
1 misplaced

Bananas present
Sign present

N/A

39

Only 250 ml cans in allcoolers and fridges

26 (84%)
1 misplaced

Bananas present
Sign present

N/A

41

Only 250 ml cans in allcoolers and fridges

25 (81%)Bananas present
Sign present

N/A

42 (Last day
banana + cereal)

Only 250 ml cans in allcoolers and fridges

23 (74%)Bananas present
Sign present

N/A

Week 743

Only 250 ml cans in allcoolers and fridges

23 (74%)Bananas present
Sign present

N/A

Week 854

Only 250 ml cans in allcoolers and fridges

21 (68%)Bananas present
Sign present

N/A

56 (Last day sodas)

Only 250 ml cans in allcoolers and fridges

21 (68%)Bananas present
Sign present

N/A

Week 957

Only 250 ml cans in all coolers and fridges

21 (68%)Bananas present
Sign present

N/A

Week 1070 (Bags implemented six
days before)

Only 250 ml cans in all coolers and fridges

12 (39%)Bananas present
Sign present

Only smaller bags are present

Week 2

Week 3

Week 6

Duus et al. BMC Medicine(2024) 22:349

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Table 3 (continued)
Day and week of feasibility test period

Sodas at the coolers

Tags at the cerealsn (%), N = 31

BananasBags for pick’n’ mix sweets

Week 1176

Only 250 ml cans in all coolers and fridges

12 (39%)Bananas present
Sign present

Old larger bags are hungin front of the new smallerbags

Week 13

86

Only 250 ml cans in all coolers and fridges

N/A

Bananas present
Sign present

Only smaller bags are present

Week 14

97

Only 250 ml cans in all coolers and fridges

7 (23%)

Bananas present
Sign present

Only smaller bags are present(looks messy)

Week 15

99

Only 250 ml cans in all coolers and fridges

6 (19%)

Bananas present
Sign present

Only smaller bags are present

2 weeks post-feasibility-test period

Only 250 ml cans in all coolers and fridges

6 (19%)

Bananas present
Sign present

Old larger bags are hung infront of the new smaller bags

4½ months post-feasibility-test period

No 250 ml cans in any of thecoolers or fridges

3 (10%)

No bananas orsigns are present

Old larger bags are hung infront of the new smaller bags

Italic font  periods outside the implementation period of the specific initiativedays of stocking (Monday, Wednesday, and Friday), thecoolers would look neat and full, while they would appear
more empty or messy on other days.
Customer responsivenessWe observed very few customers who bought any products from the coolers, and we did not get to talk to any
customers about the initiative. However, the observationsin the store showed no distinct change in customers’
behaviour around the coolers nor expressions of discontent or excitement with the initiative. In an interview
with the store manager, he explained that he believed
customers had not noticed the change.

(Table 3). During the first 3 weeks, 10% (n = 3) of thetags were missing. This portion progressively increased
to 23% until the end of the fifth week. In the sixth week,
the portion decreased at first to 16% but decreased again
and ended at 26%. In the weeks after the implementation period, the tags stayed present but slowly came off.
Approximately 6 months later, three (10%) of the tags
were still present. We observed throughout the feasibility test that the presentation of the area varied, which is
to be expected in a busy supermarket. At times, the area
looked messy; boxes would block access to some products, products would be sold out, some would change
packaging, and new products would be introduced to theselection.

Retailer perspectives

The store manager was positive about the initiative, butfrom his perspective, the decision to implement it should
be made at the procurement level and by the suppliers.
However, he did have an opinion on how to implement
it. The price needed to be fair according to the productit replaced. Moreover, he drew attention to the fact that
it was the supplier’s personnel who stocked the products
rather than his own. The store manager was, therefore,
not surprised that the employees at the store had little tosay about the initiative. føtex’s representative (B) was also
positive about the initiative and expressed in the interview that the chain would be willing to implement it—if
they found it to be the ‘right thing’ to do. However, therepresentative also emphasised the importance of agreeing with the suppliers, which is a time-consuming process and ‘not done in just six months’.
Shelf tags for breakfast cereal products

From the first day of the implementation, some tags
were missing, and one tag was consistently misplaced

Customer responsiveness

When we asked customers about the tags, we learned
that they had been unaware of them and that somebelieved that it was not something they would use—some
did not know the meaning of the labels on the tags, whileothers did not find the labels relevant for them.
[The tags] don’t matter. My wife is pretty health conscious, so we don’t use those, let alone know withsuch a thing as breakfast cereal. (Male customer)
From our observations of the behaviour of the customers in the breakfast products and cereals department, wefind two interesting groups: Those who shop alone andthose who shop together with others (primarily children).
These groups seem to practice different behaviours.
Among those who do their grocery shopping by themselves, we find two subgroups: 1) those who have planned
or know exactly what they want to buy, and 2) those who
decide at the store. For the first sub-group, we observedthat some showed this by practising a behaviour whereDuus et al. BMC Medicine(2024) 22:349

they would walk quickly and purposefully towards the
shelves and quickly pick up a product. Others would lookdetermined to find a specific product, as the fieldnote
excerpt illustrates:
A woman stands looking at the muesli. She firstgrabs an orange bag on the bottom shelf, then a moreyellow one next door and puts the first one back on
the shelf. She inspects the bag she took. She starts tolook around the shelves more and reaches for a bag
that has a pinker look on the top shelf. She puts itback and reaches into the space next to it, where
there are a few bags at the very back, but she has
difficulty reaching them. A man comes by, notices
the woman, and offers to help her. The woman indicates a yes, and the man reaches up and grabs a bag‘that’s the one!’ says the woman as the man hands
her the bag.
Another example was a man who kept looking backand forth between some muesli and granola products
and his phone before he eventually chose a product. It
is unknown whether the man was looking at a specificnote, a text request from his family, or a picture on his
phone, yet what was on his phone seemed to determine
the product he bought. Overall, this group seemed very
unlikely to be influenced by the tags, as they had madetheir choice already before they entered the store.
For the second sub-group, those who seemed to maketheir decision in the store, we observed that some would
just stop and glance at the products without choosing
one before moving on with their shopping. Others would
look more randomly at the selection than those describedabove, walk back and forth in the aisle, compare different
products and read the info on the back of the products.
For those who shopped together with others (mostoften children), we observed that when adults shopped
with children, the choices of the child and the choicesof the adult often conflicted. In one example of a childand a woman who looked at breakfast cereal products,
the child was initially allowed to pick a product andasked for different chocolate variants, which all featured
cartoon figures; however, the woman rejected all of thechild’s choices. In the interaction, the child was met withdemands from the woman regarding the attributes of the
products: they could not contain chocolate or sugar. In
the end, it was the woman who chose a product based onher experience of the child’s preferences and her criteria.
In similar situations, we did observe an attempt at compromising between the adult’s and the child’s criteria,
which was explained by this woman:
I ask them [woman and boy aged about 10] what
they look for when choosing breakfast cereals. The

Page 9 of 18

woman looks at the boy and says, ‘Well, what
are we looking for?’. The boy does not answer but
looks at her and me and smiles. The woman herself
replies, ‘Something we can agree on. Something helikes but is not too unhealthy, either’. I ask her what
she considers unhealthy. She waffles for a bit andthen replies, ‘Yes, but he wants that Lions cereal,for example, and I don’t want him to have that.
So something that’s not de facto sweets’. She takes
the box of granola that they have chosen [Paulún’s
blueberry/lemon granola] out of the basket, looks
at it and says, ‘So we chose this one. There’s probably also a lot of fructose and caramelised stuff init, but yeah.’This illustrates the high impact children had on the
choices of breakfast products, but also how the parents
tried to control and negotiate the final choice.
Retailer perspective

The store manager had little faith in the effectiveness ofthe shelf tags:
The thing about tagging cereals, I don’t think thatmakes the slightest difference. The reason why I’m
sceptical in that regard is that it’s a mixture of what
I do on a daily basis. It’s especially the behavioural
patterns of our customers, but also how I act as acustomer myself to a degree. I don’t think shelf tagswith the whole grain label or anything like that; inmy experience it hasn’t changed things much. (Store
manager)
His view on the effect of the initiative was in line with
our observations of the customers in the store. Furthermore, the store manager explained that it was difficult to maintain the initiative, as it was not part of theemployees’ daily routine. This was also the argument of
why the tags lingered after the test period—it was justnot part of the usual protocol either to hang them up or
take them down. This perspective was shared by the føtex
representative (B), who also highlighted the cost of thismaintenance.
Contrary to the store managers’ sceptics, the føtex representative (B) was more positive about the initiative:
I think it’s a good initiative. We work a lot with tags
and labels in general. [...] I think making it transparent to the consumer is really interesting because
there’s nothing wrong with buying a box of Nesquick
cereal every once in a while. At least we should not
claim it’s the wrong thing to do. But you just have to
be clear about what you’re buying, and I think thoselabels help with that. (føtex representative (B))

Duus et al. BMC Medicine(2024) 22:349

She explained that the initiative was highly compatible
with their usual strategies. However, she also explained in
the interview that a barrier to using shelf tags to promote
the buying of certain products was that the chain wastrying to reduce the printed material they used in theirstores as part of their CSR strategy and to reduce costs.
Replacement of the complimentary bun for children
with a banana

The complimentary banana was fully implemented in
the feasibility test period except for 1 day of observation, where the signs were not visible (Table 3). The initiative also remained available and present by the signfor at least 10 weeks after the implementation period.
Furthermore, the store manager informed the researcherthat they would continue to provide bananas for customers requesting this as an act of customer service.
From the observations, we do find that the presentation of the initiative changed throughout the period. At
first, the bananas were placed in a cardboard box on thedisplay counter, which was later replaced with a nicerlooking basket. The number of bananas and their colour
also fluctuated during the different days, which would
be expected due to the delivery of the bananas and how
often they are restocked. However, compared to the buns,
we never observed that the bananas were not available,
making it a reliable offer no matter the time of the day.
Customer responsivenessWe observed two ways (1 and 2) that the complimentaryoffer for children was brought up: 1) A customer would
ask for the ‘bun for children’, or 2) the staff would offer
the complimentary banana to buying customers. In thefirst way 1), we saw two responses from the staff (a andb) and the customers (i and ii): (a) The customer would
be offered the bun with no mention of the banana, or (b)the staff would inform the customer that they no longer
offered buns but that they offered a banana instead.
The customers had two primary responses to this message: (i) The customer rejected the offer and decided tobuy a bun or another item instead. The child was often
included in this decision. (ii) The customer accepted theoffer and received the banana. In some cases, the childdid not accept the offer and the customer compensatedfor this response by buying a bun or another product forthe child. In the second way 2), in which the staff offered
the banana spontaneously, the customers almost always
reacted positively and accepted the offer.
The following excerpt illustrates why some customers
rejected the offer:
A woman with a child of about 1-year-old in astroller walks up to the bakery and asks for a chil-Page 10 of 18

dren’s bun. The child has already noticed the bunsfrom the moment they arrive and sits, pointing at
the buns through the glass window and babbling.
The shop assistant says that there are no children’sbuns but bananas and points to the sign. The woman
replies, ‘I’d like to buy a bun, then’. The assistanttakes the bun and enters it into the till, while thewoman says, ‘Bananas are so messy’. The assistantsmiles and says, ‘Well yeah, I’ll pass that on’. The
woman replies, ‘It’s just that the banana is rather abother, and the assistant replies, ‘But I think we’ll beoffering [the buns] again eventually’.
Thus, adults rejected the offer because eating a banana
was a messier process than eating a bun. During meetings and interviews, the retailer also highlighted thisas the main reason for rejections of the offer, especiallyamong those with younger children. Another reason forrejection was that the parents did not appreciate the offer
nor perceived a need to offer their children a banana
instead of a bun.
Retailer perspective

This initiative was the most successful and interesting
one in the eyes of the store manager.
I’d like to highlight the banana for kids, which isclearly the initiative I found most customers werepleased with. (Store manager)
Many customers responded positively to the new offer,
which was emphasised as a marker of success. It was also
the reason why the initiative continued after the 6-weekperiod, and the store manager explained that they would
continue to give bananas to those who asked for them.
The following excerpt illustrates what the bun meant toføtex and the chain’s relationship with its customers.
The children’s bun has been around for donkey’s
years, and it’s become ingrained in parents and kids
alike that you can get them in føtex. So, we’re quite
interested in learning how many people would actually, if presented with the alternative, choose something else, like, for example, the banana. I’m quite
surprised by that – we can’t track it, unfortunately– but off the top of my head, up to 40 to 50 percent
actually choose the banana. I find that very interesting. (føtex representative (B))
Thus, it came as a surprise that the initiative was sowell received. However, despite the positive experienceswith the initiative, the retailers also commented on thecost. They highlighted that the banana was more expensive than the bun, and if it should be an option offeredin all stores, then it would have to be prioritised at theDuus et al. BMC Medicine(2024) 22:349

executive level as an additional expenditure. In this case,the banana would only be an alternative to the bun andnot a replacement. This was rationalised by the retailers’ attitude of not making choices on behalf of thecustomers.
Smaller bags for pick’n’ mix sweets

This initiative was not implemented until 8 weeks after
the initial implementation date. It was fully implemented
for five out of the six weeks; during the third week, weobserved that the old, larger bags had been hung infront of the new smaller bags. At 2 weeks and four anda half months after the feasibility test, the smaller bags
could still be found behind the larger bags—however, it
is unlikely that these would have been used, as the obvious choice would have been the bag at the very front. As
described for the other areas, this also fluctuated in its
presentation and stocking.
Customer responsivenessWe did not get any direct reactions from customers on
the smaller bag. However, our observations showed thatdifferent strategies were used to decide the amount ofcandy among customers who bought pick’n’mix sweets.
Some showed signs of visually assessing the amount ofsweets in the bag, which were the customers we would
expect to influence. We often observed this strategy
among adults with children, where it was the adult who
would visually assess the amount and communicate to
the child when they had picked enough.
Those with very young children would walk alongside
the child and select the sweets for them, and some adults
would encourage the choice of the child by pointing out
different variants and commenting on the appearance ofthe sweets.
Other strategies were to mix according to a pre-defined
number of pieces or volume:
A boy of about 10 and a girl of about 8 come overand mix sweets. They repeatedly weigh the bag while
doing so. A woman comes over, and the girl says,‘Hello mummy!’ The woman says, ‘Don’t forget toweigh it’. She then grabs a bag herself and begins tomix sweets. The boy asks the girl, ‘Did you weigh it?’.
The girl walks over to the scales and says, ‘I think
I’ve got enough’. However, she does not close the bag,and she begins to walk around somewhat restlessly,
then says, ‘I don’t know what to pick. I’m still [a few]
grammes short’.
An interesting aspect of the situation above is that thegirl expressed that she was satisfied with what she hadchosen, but she felt that she had to meet the prespecified
weight and, therefore, tried to find more sweets to put

Page 11 of 18

in her bag. Such strategies undermine the mechanism
which the initiative was trying to influence.
Retailer perspective

Overall, the retailers were positive about this initiative.
The føtex representative (B) highlighted that this initiative was interesting as it was a stealth initiative, compared to the initiatives with the sodas, and would change
the behaviour of the customers without them noticing. In
her opinion, this was not a problem, as people paid pergram.
The store manager had a clear demand for the implementation; it should be easy for both the staff and customers to use. This perspective was backed up by a føtex
representative (B) who said:
If there’s something that doesn’t work for us, it’s... if it
doesn’t work for our customers, that’s what we needto solve first. (føtex representative (B))
This shows how one success criterion of the retailers iscustomer satisfaction, which we elaborate on later (See:Influence of customers and other stakeholders on store
operation).
The initiative was very delayed, and one reason wasthat it was challenging to create a new bag that would
work in the store. This resulted in the order of many different bags in large quantities due to the agreements withthe suppliers, which had been very costly for the retailer.
The føtex representative (B) also reflected on what thepotential evidence of an effect would mean to the retailer:
Then we’ll have to wait and see if people buy fewer
sweets. And of course, this is something that we musttake into account because it’s no secret that part ofbeing a responsible business is to make a profit. And
if we sell fewer sweets, then we make less money.
(føtex representative (B))
This shows how health and financial profit were seen as
opposites and how the success of the initiative would notnecessarily lead to it being viewed favourably, as it would
negatively affect their profit. Any implementation in the
chain would, therefore, have to be a strategic decision.
Facilitators and barriers

In the sections above, we have focused on the four specific initiatives. In the following, we will present analytical findings that go across the initiatives and elucidate
what facilitated and hampered the implementation of theinitiatives overall. We have organised our findings under
three headings: Health is not the number one priority;
General capacity of the retailer; and Influence of customers and other stakeholders on store operation.

Duus et al. BMC Medicine(2024) 22:349

Page 12 of 18

Health is not the number one priority

However, from the interviews with the retailers andour fieldwork, it seemed that this was not completely
black and white, as the retailers were willing to giveup their profit in some cases. An example is the hiding of tobacco products in all Salling Groups’ supermarket chains, which they voluntarily implemented in2018, which led to a significant decrease in profit fromtobacco products.

In this section, we present the retailers’ motivation
for and interest in engaging in the project and working
with health and health promotion and what drives and/or curbs this motivation. In our understanding of motivation, we draw on Scaccia et al. [33] and view motivation as incentives and disincentives that contribute to thedesirability of using an initiative focusing on health.
We find that the retailers expressed motivation forworking with health and health promotion, which at
first seemed to be based on interest. The retailer representatives explained how they personally were interested
in health and wanted to learn more, but also that theorganisation had an interest in health, especially amongchildren and young people, and wanted to contribute tohealth-preventing activities, for example, by financially
supporting local sports clubs. According to one retailer
representative, this was because physical activity andhealthy eating promote happier customers, as well as
happy employees. The argument points to retailers’ focus
on customer satisfaction (see: Influence of customers andother stakeholders on store operation). The focus on thecustomers relates to another factor of motivation: Working with health was also seen as a relative advantage inthat customers increasingly demand healthier products
and alternatives. Lastly, we found that the motivation forworking with health was a feeling of obligation due to theview of having a social responsibility:
I would say, in purely business and commercial
terms, we are, indeed, a commercial business thatwas created to make money. There’s no ignoring that(laughs). So, of course, this is our main KPI [key performance indicator]. But that being said, we also
agree that we have a social responsibility because
we are as big as we are. We make a lot of foodstuffs
available to the Danes, as do many of our colleagues
in our industry, so there is no doubt that we havea role to play in terms of what we make available.
(føtex representative (A))
According to the excerpt, this obligation was rooted
in the size of the organisation and, thereby, the major
influence on people’s selection of food products. However, the excerpt also highlighted that health was nottheir first priority, which was profit. This point has been
repeatedly mentioned among retailers, which reinforces
its validity; they were a business and had to gain profit
to keep running their operation, which presented limits
for what could be implemented. The store manager evenexpressed how he perceived the running of a supermarket and promotion of public health as incompatible goals
and something he had never seen an example of in a reallife supermarket.

After all, the Salling Group pioneered this withtobacco products. I’m proud of that, but I also
think it’s the right thing to do. My personal opinion is that it was the absolutely correct move theychose to make, by making it harder to market a
product that is obviously bad for my health. We’renot there with pick‘n’mix sweets just yet, in that wewould claim they’re bad for your health, but themindset in terms of; that is, upholding the mindset
when it comes to cigarettes is something that we,as an industry, can easily support in close cooperation with, among others, yourselves [researchers]
and the industry. (Store manager)
Risk seemed to be the driver. If the retailer was convinced that the risk was real or big enough, then they
were willing to give up some of their profits because
it was the ‘right thing to do’, and they would have thecourage and power to do so. It was mentioned by all
three informants that they did not believe in bans, limitations or hiding of products, as this interfered withthe customer’s freedom of choice. This viewpoint was abarrier to the implementation of all initiatives that usedstrategies that would minimise or reduce the availability of a product. Yet, as with the tobacco products, wefound other examples where this restriction of choice
was justified by the retailer. One example was that theføtex chain only sold organic bananas. From a sign inthe store, this was because:‘we want to avoid the spray agent chlorpyrifos.
Among other things, it is suspected of harming thedevelopment of children and foetuses. We can’t livewith that suspicion and therefore you can only buy
organic bananas in the future’
As with the cigarettes, the argument here was thehealth risks. In the interview with the store manager
about restricting choices, animal welfare and political reasons (e.g. Russia’s warfare against Ukraine) werementioned as other arguments for doing so.
So, despite an immediate motivation for working withhealth, the retailer also expressed how other interestsand priorities may hinder and set aside the work withhealth.

Duus et al. BMC Medicine(2024) 22:349

General capacity of the retailer

This section presents our findings relating to the generalcapacity of the retailer in the form of resources, organisational size, and culture. General capacity is understoodas the readiness or ability to implement any new initiative[33].
Through the interviews with the føtex representative(B) and working together with the retailer during the project, we have found that the retailer seemed to be used
to and willing to implement new initiatives. In this current study, they accounted for all expenses related to thedevelopment of materials for the test and were also willing to risk some of their profit for a short period of time.
The føtex representative (B) highlighted this high level ofavailable resources several times in the interview:
I have some leverage, so when we do something, wedon’t do it by halves. What I find most motivating,and I can say that with complete peace of mind,
is that if the Salling Group says they’re going to dosomething, or if føtex says they’re going to do something or says they want to win this particular battle,
then we win it, and then we do it to the full. [...] So
when we say, for example, with this health project,that ‘we want to work with health,’ then we do want
to work with health, and we’re going to make a difference in health, too. (føtex representative (B))
In this excerpt, she expressed that the mere size ofthe company allowed them to push any agenda if theywanted to. However, this also underlines that this capacity is dependent on the retailer’s willingness, a willingnessthat was not in favour of many of the initiatives that the
researcher, based on the literature, thought would havethe greatest effect.
Even though the size of the company came with many
available resources, the retailer also explained how thesize of the company had worked against the project inseveral ways:
What I think made it difficult for us to get throughwith some of these things let’s just take the sodas, inthat case, we have a private label collaborator who
has production facilities, and when they press the‘Salling sodas’ button, it doesn’t just spew out a few
thousand bottles, but millions. So saying ‘can’t wejust try to reduce the size and give it a try.’ It’s a giant
setup, so it’s not possible to do that at a whim. You’dneed to get a whole or half chain on board that canhelp sell such volumes because otherwise, the costs
would go through the roof. (føtex representative (A))
What this excerpt explains is that even changes thatappeared small would take tremendous effort and be very
costly, due to the size of the organisation.

Page 13 of 18

Another challenge of the implementation was embedded in the retailers’ organisational culture. Føtex representative (B) explained in the interview that conflicting
goals between employees made it difficult and timeconsuming when implementing new initiatives. Anotherbarrier to implementing the initiatives was high staff
turnover at the retailer. In an interview with a føtex
representative, she explained that people often shiftedaround different positions in the organisation, which
ended in the project falling between two stools, leading
to misunderstandings of agreements and changes in attitudes towards the initiatives.
In summary, we find that the retailers could, in somerespects, have a strong general capacity to implement
new initiatives by having available resources and being
used to implement new initiatives. Regardless, this study
shows that this was not utilised due to a lack of willingness. Moreover, we find that the size and organisational
culture of the retailer hampered the implementation of
the initiatives.
Influence of customers and other stakeholders on store
operation

The last section reports on the influence of customers on
the retailer’s willingness to implement the initiatives, andthe influence of other stakeholders, especially producers,
on what can be implemented.
We found that the customer’s reactions and attitudes
were determining to the retailer when implementing any
new initiative, as indicated in the sections above. According to the retailer, the customer was the focus when
designing the layout of the store:
We are in very close dialogue with our clients, we doquantitative surveys and we do focus groups, we doin-depth interviews. And in that context, we’re trying to understand, when you’re shopping, how do you
go about it. Is it easy for you to find the items you
are looking for? And based on the responses, we try
to adapt our stores to make things easy for our customers. (føtex representative (A))
The same representative also mentioned that she
thought it would have been a strength of the project tohave conducted interviews with the customers as a partof the development process, emphasising the weight they
put on the customer’s attitudes. The retailers highlighted
the importance of customer satisfaction and conveniencein their shopping experience as a barrier to implementing certain initiatives, such as changing the placement of
products. However, these same factors have also provento be facilitators for other initiatives, such as the tags forbreakfast products and the complimentary banana forchildren, as demonstrated above.

Duus et al. BMC Medicine(2024) 22:349

Another important stakeholder for the supermarkets
was the suppliers of their products. Others were government actors (e.g. the Danish Veterinary and Food Administration). For both downsizing initiatives, the suppliersof the products (sodas and bags for sweets) were key tothe success of their implementation. In an interview withthe store manager, he explained the huge role some ofthese suppliers have in the daily operation of the store
and the chain.
After all, we’ve got a chain agreement that our head
office has made with the breweries. I don’t get todecide which items are in our refrigerators. [...] The
tricky thing is that we’re not only dealing with føtex
or the Salling Group. We also have to do with someother, equally large companies that are also justcoming in. Plus, I have people here X times a week
to service their particular area. [...] [Another thing]that proved tricky, as far as I recall, was that thealternatives offered, people felt strongly about thosebecause the breweries made some strategic choices,and because of those, some of the items that wemight be able to stock, they didn’t want to sell those.
(Store manager)
This excerpt illustrates how suppliers like the breweries, as shown earlier, influenced the implementation andaffected the decisions made by the retailer.
This section indicates that even though the retailer isconvinced that a given initiative would be interesting to
implement in their supermarket, the suppliers often must
agree as well, and finally, the customers must also welcome it.

Discussion
In this study, we have explored the implementation,
acceptability, and feasibility of four different healthpromoting food retail initiatives aimed at customers in areal-life supermarket setting, using different qualitative
methods. We found that (i) Two initiatives (downsizingof bags for the pick’n’ mix sweets and the complimentary banana for children) were implemented to a highdegree, yet delivery issues caused delays according to theplanned date, especially for the bags. The downsizing of
soda bottles was not implemented as intended; the sizeand packaging deviated from the original plan due todelivery failure. Moreover, the implementation decreased
over the feasibility test for the initiative with shelf tags,
as it took more continuous maintenance. For all initiatives, we found that they lingered after the feasibility test;
however, only the banana for children was somewhat sustained for a period to accommodate customer demand.
(ii) The retailers expressed different levels of acceptability towards the initiatives, and different representatives

Page 14 of 18

sometimes also showed different levels of acceptability
towards the same initiative, such as the tags on the breakfast products. The most well-received initiative was thebanana for children, which is somewhat unsurprising, as
it was the retailers themselves that suggested including
this initiative. Additionally, the positive response fromthe customers that they got supported the retailers’ positive attitude towards the initiative. We also found thatmany customers responded well to this initiative; however, we also observed a group that did not accept theinitiative and preferred the bun over the banana. For theremaining initiatives, customers did not seem to noticethem. Yet, we did observe customer behaviours thatwould probably work against the suggested mechanismsof some of the initiatives. (iii) In general, we describe
three themes of barriers and facilitators that influence
the implementation and possible sustainment of the initiatives: Health is not the number one priority, Generalcapacity of the retailer, and Influence of customers andother stakeholders on store operation. Firstly, we found
the retailers were motivated to work with health, bothfrom a personal and professional perspective. The motivation was rooted in a feeling of social responsibility as
well as health initiatives being viewed as a relative advantage, due to demand and making customers happier. Still,other priorities, such as profit and maintaining customers’ ‘free choice’, challenged the motivation to implement
such initiatives. Secondly, the retailer showed a high levelof available resources, which supported their generalcapacity to implement the initiatives; however, the large
size of the organisation and its culture proved to be barriers to the implementation. Lastly, the analysis showedthat the influence of both customers and other stakeholders was crucial to the implementation, both in terms ofwhat is possible and what the retailers would be interested in and prioritise.
Our findings are similar to those of others [26, 35].
Winkler et al. [35] found that even though supermarket
actors found health-promoting initiatives meaningful toengage in, their engagement was challenged by a business mindset, practical routines, and structural requirements. Thus, despite the involvement of retailers in thedevelopment, selection and implementation of the initiatives, studies suggest that healthy food retail initiatives
still encounter some fundamental barriers towards theimplementation, such as the economical aspect or theview on customers’ free choice. However, our results also
indicate that it might be possible to persuade food retailers to remove products or restrict choices if the evidenceor arguments of it being the right thing to do are sufficiently strong, as with organic bananas or tobacco products. This has also been the case of another retailer inDenmark, which has decided that all their stores should

Duus et al. BMC Medicine(2024) 22:349

be tobacco and nicotine-free by the end of 2028 to reduce
the number of smokers [36]. Another solution is to identify win–win initiatives, as the complimentary banana forchildren was somewhat an example of (if we consider thebanana as a healthier alternative) and which other studies
have found as well [35, 37].
Even though the four initiatives were implemented (yettwo not as intended) in this study, and we found them
to be somewhat acceptable to the retailers, we must still
highlight that these initiatives represent a very small portion of the initiatives first suggested and entail several
compromises from what the researchers had initiallyplanned (Duus et al. Unpublished). Moreover, the customer’s responses to the initiatives were mixed, and insome cases, their behaviour indicated that the initiatives
would have little effect. Compared with studies testing
similar initiatives, we find that 1) Shelf tags alone were
found unlikely to change food purchases [38] and arelikely to contribute to disparities in food purchases as not
all customers know nutrition labels or have the literacy toread and understand them [39]. 2) Smaller bags for pick’n’
mix sweets could be successfully implemented and, basedon results from another study, might be able to decrease
the volume of sweets sold [40]. Moreover, others havealso shown that customers are willing to buy smaller
product options [41]. Taken together, this suggests thatvoluntary engagement with researchers might not suffice
to make changes that would improve the supermarket
environment as opted for to support population health.
This view has also been suggested by Winkler et al. [35],and in the Lancet series on commercial determinants ofhealth, an even more critical perspective on engagementswith commercial actors as food retailers is presented [42,43]. Here they warn against how commercial actors use
partnerships with researchers, among others, as a tool toimprove their reputation and credibility [42].
In our collaborative process with the retailer, we experienced many challenges. We did not accomplish aligning retailers’ and researchers’ interests as scholars havesuggested being the prerequisite of implementing healthy
food retail interventions in supermarkets [26, 27]. This
underlines the importance of the pre-intervention phase,as described by Hawe, Shiell, and Riley [44], which isfundamental to a successful implementation. During the
pre-intervention phase, the establishment of relationships between different people or agencies often occurs,
and these relationships may play a crucial role in theimplementation and the explanation of why some workand others do not [44]. In line with this, another study
has suggested exploring what implementation strategies
might promote the uptake of evidence-based interventions among food retailers [45]. They found that contrary
to many other studies, the intervention in their study

Page 15 of 18

was compatible with the interest of the store managers
to which it was presented—these store managers had astrong feeling of social responsibility towards the communities they operated in [45].
Strength and limitations

The investigation of the feasibility test was strengthenedby using different methods, process evaluation concepts,
and a broad view including both the delivery and presentation of the initiatives as well as customer and retailer
perspectives. We primarily got the retailer perspectivefrom a strategic level, yet we had planned on conducting focus group interviews with staff at the test store to
get perspectives from an operational level on the initiatives and the implementation process. However, no staff
wanted to participate in an interview. The store manager
explained that this probably was due to three things: 1)
They had no interest in the study, or they were tired of
the study, 2) the recruitment was done too late (approximately 2 months after the feasibility test period), and 3)
the staff was overworked as a result of understaffing due
to the coronavirus disease pandemic. Future studies aim
also to analyse sales data in order to evaluate whether
any changes in sales of the products we intervened on
occurred. However, with the available data, we will not
be able to analyse whether the initiatives change people’s
eating patterns or whether they influence people differently in terms of their socioeconomic factors or othercharacteristics.
A thorough needs assessment [46] among supermarket
customers to test the initiative’s assumptions and theirfood purchase patterns would have strengthened thestudy. However, this was not possible within the timeframe and funding scheme, so the development drew primarily on existing knowledge and the experience of theretailer and the Danish Cancer Society. Furthermore, thestore visits conducted in the store during the development of the initiative also provided a few customer perspectives, which led to the exclusion of some ideas (Duuset al. unpublished).
Furthermore, we learned two methodological lessons
from the in-store observations: 1) All observers were metby the feeling of being ‘in the way’ and a need to be inalmost constant movement to not interfere with the orderin the store. The observers were met with a feeling of selfawareness and a need to legitimise their presence at thestore by wearing a sticker on their shirts saying ‘visitor’or their university identification card. These feelings were
amplified by the governmental advice of social distancing and the requirement to wear face masks in grocery
stores, introduced during the period of observations. 2)
Concerning this, the observers also found it challenging
to approach customers for the short interviews due to theDuus et al. BMC Medicine(2024) 22:349

feeling of invading people’s private space, hence only fivewere conducted. This was especially challenging when
wearing face masks, as it was impossible to produce andread non-verbal signals (e.g. smiles), and difficult to hear
what people were saying.
Implications for future studies and practiceThis study presents an investigation of the implementation of healthy food retail initiatives for supermarkets
that have been developed and selected together withretailers as suggested by the literature. It suggests thatthe implementation of such initiatives is possible and—tosome degree—high. Yet, the quality of the initiatives wasrather low, and some were not implemented as intended.
Moreover, we still present some of the same barriers andlimitations as former studies that have not implemented
collaborative strategies in the pre-intervention phase.
Some of this may be due to challenges such as a high staff
turnover at the retailer and a lack of a shared understanding, as shown in another study (Duus et al. unpublished).
Future studies must explore this further.
Lessons for future studies are to identify initiatives
that customers appreciate, as this is important to retailers. Underlining a needs assessment as an important firststep in intervention development [30, 46]. Furthermore,
future studies should involve a broader range of stakeholders, including manufacturers and suppliers, in thedevelopment of the initiatives, as they have significant
power over what can be implemented. Future studies
would also benefit from identifying and testing implementation strategies that can facilitate the implementation of this type of intervention in this setting.

Conclusions
We performed a qualitative investigation of the implementation, acceptability, and feasibility of four different
healthy food retail initiatives aimed at customers in areal-life supermarket setting, which had been developed and selected together with retailers. Only two of
the four initiatives were implemented as intended, andthe perspectives of retailers and customers were mixed
or unclear. Altogether, the study highlights the challenges of implementing healthy retail food initiatives
despite early involvement of retailers in the selection
and design of those initiatives. Adding to the challengesof implementation, the initiatives also represent a compromise between the interests of the researcher andthe retailers and do not represent what the literaturesuggests as the most effective strategies. A compromise made to uphold the partnership and complete thefunded research project. Future studies should further
examine the impact and pitfalls of including retailers(or other commercial actors) in the development andPage 16 of 18

selection of healthy food retail initiatives and try to
identify successful implementation strategies facilitating implementation.
Abbreviations
CSR	Corporate Social Responsibility
KPI	Key Performance Indicator

Supplementary Information
The online version contains supplementary material available at https://​doi.​
org/​10.​1186/​s12916-​024-​03561-2.
Supplementary Material 1.
Supplementary Material 2.
Acknowledgements
We want to thank all the participating retail group and supermarket staff
members involved in this project and the implementation process. We
appreciate the time and effort you have dedicated to this project and youropenness. Furthermore, we want to acknowledge the customers who took
the time to share their opinions with us during their daily grocery shopping.
We acknowledge Johanne Aviaja Rosing, Louise Ayoe Sparvath Brautsch, andCarl Johannes Middelboe for their assistance in conducting the pre- and postintervention observations.
Authors’ contributions
KSD, RFK, and TTT contributed to the funding acquisition, study concep‑
tion and design. Data generation and analyses were performed by KSD. The
first draft of the manuscript was written by KSD. RFK and TTT commented
on previous versions of the manuscript and contributed in writing the final
manuscript. KSD wrote up the final manuscript. All authors read and approved
the final manuscript.
Funding
Open access funding provided by University of Southern Denmark This study
is funded by the Danish Cancer Society, grant no.: R274-A16920. The firstauthor (Katrine Sidenius Duus) has also received a Faculty Scholarship fromthe Faculty of Health Sciences at the University of Southern Denmark to sup‑port the completion of her PhD thesis, which this study is part of.
Availability of data and materials
The data generated and analysed during the current study are not publicly
available due to their sensitive and confidential nature but are available fromthe corresponding author upon reasonable request.

Declarations
Ethics approval and consent to participate
This study has been approved by SDU Research & Innovation Organiza‑tion (notification no. 11.136). All informants who participated in interviewsreceived written and verbal information about the aim, that participation was
voluntary and that their information would be used for research purposes only
and treated with confidentiality. By participating, consent for their data to be
used for research was given. Data from the observation and documents werehandled confidentially and with caution to protect sensitive information that
could identify individuals.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Author details
1
The National Institute of Public Health, University of Southern Denmark,Copenhagen, Denmark.

Duus et al. BMC Medicine(2024) 22:349

Received: 24 May 2024 Accepted: 14 August 2024

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