Clinical trial NCT05399836: SSS and the Impact of Portion Size on Daily Energy Intake
Official title: Subjective Social Status and the Effect of Portion Size Reduction: a 1-day Dietary Behaviour Experimental Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diet, Healthy
Eating Behavior
Obesity
Keywords: portion size
socio-economic position
eating behaviour
Lead sponsor: University of Liverpool
Sponsor class: OTHER
Collaborators: name: European Research Council
First posted: 2022-06-01
Enrollment: 47
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: Reducing food portion size is a potential strategy to reduce energy intake. However, it remains unclear who is most susceptible to the portion size effect (PSE). There are just two studies which have examined the PSE in the context of socioeconomic position (SEP), with mixed findings. In an online trial the PSE on intended consumption of unhealthy snacks was 18-24% larger for participants of lower SEP compared to participants of higher SEP. However, in a recent laboratory study which examined the PSE on total daily energy intake, participants of lower SEP were no more susceptible to the influence of portion size on eating behaviour than participants of higher SEP. Further research is required to elucidate these divergent findings.

There is also an absence of evidence examining the moderating role of subjective social status (SSS) - an individual's perceived standing in society - on the PSE. Given evidence that the subjective experience of social class may be associated with health outcomes, the present study examines whether reductions to the portion size reduces daily energy intake, and whether and how SSS (higher vs lower) moderates the PSE.

In a crossover experiment, participants will be served all meals in the lab on two separate days, with the portion size of main components at breakfast, lunch and dinner manipulated (i.e. smaller on one day vs larger on the other day). All other foods offered are identical. Food intake from the portion-manipulated breakfast, lunch and dinner, as well as all other meal components (non-portion-manipulated sides, dessert, seconds, snacks, etc.) will be measured, to assess total daily energy intake (kcal).

Detailed description: See Study Protocol attached.

Eligibility criteria: Inclusion Criteria:

* Female
* UK (United Kingdom) residents, able to visit laboratory in Liverpool
* Aged 18 or over
* Fluent in English
* willing to consume the test foods
* Self report willingness to eat test foods
* BMI between 18.5 - 32.5kg2

Exclusion Criteria:

* participation in our previous study
* food allergies, intolerances or specific dietary requirements (except vegetarian)
* taking medication which affects appetite
* currently pregnant
* history of eating disorders
* currently on a diet to lose weight

Primary outcomes:
measure: Daily energy intake
timeFrame: Time Frame: 24 hours after intervention administered
Secondary outcomes:
measure: Energy intake from portion-manipulated foods
timeFrame: Time Frame: 24 hours after intervention administered
measure: Energy intake from non portion-manipulated foods
timeFrame: Time Frame: 24 hours after intervention administered
Other outcomes:
Locations:
city: Liverpool
country: United Kingdom
facility: University of Liverpool
Study officials:
affiliation: University of Liverpool
name: Eric Robinson, PhD
role: PRINCIPAL_INVESTIGATOR
References: