A Small Nudge for Better Health Through Reduced Salt Intake, Increased Vegetable Intake, and Smaller Portion Size

Study Overview
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Brief Summary
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This study will investigate whether small changes (nudges) made in a cafeteria, where participants eat for 4 weeks, can improve their food behavior and health during the 4 weeks, and 6 weeks and 6 months after their stay. Half the participants will be exposed to one of four types of nudges (focused on reducing salt intake, increasing vegetable intake, reducing portion size, and a combination of these nudges), and half of the participants will eat in the cafeteria as it is currently, without modifications.

Detailed Description
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A healthy diet is an important pillar for public health and for the prevention of several lifestyle diseases (e.g. obesity, cardiovascular diseases). However, diet choices are often not conscious choices. While it may help to make individuals more aware of healthy options for example through education or nutrition labels, it remains difficult for many to eat healthy. The food environment in which choices are made has an impact on the choice. Smart design of the food environment may help individuals to make a healthier choice, by nudging them towards the healthier alternative, while not limiting the availability of the less healthy choice. This study tests how these 'nudges' can affect food behavior and health of participants in a 4-week rehabilitation course at Feiring Heart clinic. Nudges will be implemented in the cafeteria at the clinic. Three types of nudges will be tested: Salt nudge: aims to reduce salt (sodium) intake. Salt will be less easily available in the cafeteria, and other spices (without sodium) will be made easily available. Food in the buffet that is either very high or very low in salt will be labeled. Vegetable nudge: aims to increase vegetable intake. Names of the vegetable dishes in the buffet will be made more attractive, signs will be placed with reminders to eat more vegetables, and with visual indications of the percentage of vegetables that should be part of a meal. Portion size nudge: aims to decrease portion size. Smaller plates will be provided, and utensils for self-serving calorie-dense foods in the buffet will be smaller than normal. One period will also combine all the nudges described above. Outcomes include measures of food intake during the 4-week rehabilitation course, and whether food habits 6 weeks and 6 months after the 4-week course have changed, compared to before the course. BMI will be monitored during the 4-week period and self-assessed in the 6 months after. Physical activity habits will be considered during the entire experimental period, and satisfaction with the cafeteria food and service will be monitored throughout to assess whether the nudges impact customer satisfaction. Results are expected to be transferable to other heart clinics, and cafeterias in other institutions.

Official Title
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Nudging: How Small Changes in the Cafeteria of the Feiring Heart Clinic Can Result in a Healthier Food Choice.

Conditions
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Cardiovascular Disease, Obesity

Intervention / Treatment
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* Behavioral: Nudged to eat less added salt and more other seasonings
* Behavioral: Nudged to avoid foods high in salt content, and to choose foods low in salt content
* Behavioral: Nudged to eat more vegetables
* Behavioral: Nudged to eat smaller portions
* Behavioral: Nudged to eat less calorie-dense food


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants should be part of the 4 week rehabilitation course at the Feiring heart clinic Participants should be willing and able to complete the necessary registration of food choices, and the relevant questionnaires Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Salt nudge<br>The following changes will be made in the cafeteria: Salt will be placed in a corner of the buffet, rather than on each dining table. Other spices, without sodium, will be provided on the table. A sign will be placed on the table that nudges participants to try the other spices. Food in the buffet that is high in salt will be labeled with a negative-appearing symbol, and food in the buffet that is low in salt will be labeled with a positive symbol. | Behavioral: Nudged to eat less added salt and more other seasonings<br> <br> Behavioral: Nudged to avoid foods high in salt content, and to choose foods low in salt content<br> <br> |
| Experimental: Vegetable nudge<br>The following changes will be made in the cafeteria: Names of the vegetable dishes in the buffet will be made more attractive. Signs will be placed with reminders to eat more vegetables. Signs will be placed with a visual indication of the percentage of a meal that should consist of vegetables. | Behavioral: Nudged to eat more vegetables<br> <br> |
| Experimental: Portion size nudge<br>The following changes will be made in the cafeteria: Smaller plates will replace the regular plates. Verbal and visual nudges to reduce portion size will be given. Utensils for self-serving calorie-dense foods in the buffet will be smaller than normal. | Behavioral: Nudged to eat smaller portions<br> <br> Behavioral: Nudged to eat less calorie-dense food<br> <br> |
| Experimental: Combined nudge<br>All three nudges are combined in this intervention. | Behavioral: Nudged to eat less added salt and more other seasonings<br> <br> Behavioral: Nudged to avoid foods high in salt content, and to choose foods low in salt content<br> <br> Behavioral: Nudged to eat more vegetables<br> <br> Behavioral: Nudged to eat smaller portions<br> <br> Behavioral: Nudged to eat less calorie-dense food<br> <br> |
| No Intervention: Control groups<br>No changes are made to the cafeteria, compared to the pre-study situation. One control group participates after each of the nudges to control for effects of time of the year. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in BMI from start of intervention to end of intervention | BMI is measured, and change in BMI between day 0 and day 28 is used. | Measured at baseline at day 0 of intervention and at completion of intervention at day 28 of intervention) | 
| Change in dietary habits 1 | Habits are compared with habits as listed before the start of the 4 week intervention period. Done through an online survey. | 6 weeks after the 4 week intervention period | 
| Change in dietary habits 2 | Habits are compared with habits as listed before the start of the 4 week intervention period. Done through an online survey. | 6 months after the 4 week intervention period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dietary choices in cafeteria 1.1 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Tuesday lunch meal during the first week of the intervention | 
| Dietary choices in cafeteria 1.2 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Thursday lunch meal during the first week of the intervention | 
| Dietary choices in cafeteria 2.1 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Tuesday lunch meal during the second week of the intervention | 
| Dietary choices in cafeteria 2.2 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Thursday lunch meal during the second week of the intervention | 
| Dietary choices in cafeteria 3.1 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Tuesday lunch meal during the third week of the intervention | 
| Dietary choices in cafeteria 3.2 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Thursday lunch meal during the third week of the intervention | 
| Dietary choices in cafeteria 4.1 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Tuesday lunch meal during the fourth week of the intervention | 
| Dietary choices in cafeteria 4.2 | Participants make photos of their meal including drinks, and register any condiments or seasoning added | Thursday lunch meal during the fourth week of the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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behavior, food intake, salt, vegetables, portion size, weight loss, habits