SEP and the Impact of Portion Size on Daily Energy Intake

Study Overview
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Brief Summary
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Reducing food portion size is a potential strategy to reduce energy intake. There is some evidence to suggest that individuals with lower socioeconomic position (SEP) intend to eat more from larger portions, suggesting that the effect of portion size on food intake might vary by SEP. However, no study has tested this by measuring actual food intake. This study examines whether reductions to the portion size of components of a main meal will reduce daily energy intake, and whether and how socioeconomic position (higher vs lower) moderates the portion size effect. In a crossover experiment, participants will be served all meals in the lab on two separate days, with the portion size of main meal components at 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 lunch and dinner, as well as all other meal components (breakfast, dessert, seconds, snacks) will be measured, and any additional food consumed by the participant will be measured using self-report, giving total daily energy intake (kcal).

Detailed Description
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See attached protocol document.

Official Title
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Socioeconomic Position and the Effect of Portion Size Reduction: a 1-day Dietary Behaviour Experimental Study

Conditions
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Diet, Healthy, Eating Behavior, Obesity

Intervention / Treatment
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* Behavioral: Portion size manipulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female UK (United Kingdom) residents, aged 18 or over Fluent in English willing to consume the test foods Self report liking of test foods BMI between 22.5 - 32.5kg2 Exclusion Criteria: taking medication which affects appetite currently pregnant history of eating disorders currently on a diet to lose weight food allergies, intolerances or specific dietary requirements (including being vegetarian or vegan) participated in 2018 Mood Study currently participating in another study where meals are provided

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Larger portions<br>the main meal component (lunch/dinner) served to participants in the laboratory, reflecting 100% portion. All other foods are identical across conditions (e.g. sides, seconds, breakfast, dessert, snacks). | Behavioral: Portion size manipulation<br>* The intervention was administered via changing portion sizes of foods served to participants.<br>|
| Experimental: Smaller portions<br>the main meal component (lunch/dinner) served to participants in the laboratory, reflecting 66% portion (i.e. reduced portion size). All other foods are identical across conditions (e.g. sides, seconds, breakfast, dessert, snacks). | Behavioral: Portion size manipulation<br>* The intervention was administered via changing portion sizes of foods served to participants.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Daily energy intake | Total energy (kcal) consumed from breakfast, lunch, dinner, dessert, snackbox, and any self-reported additional foods. | 24 hours after intervention administered | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appetite | Hunger and fullness sensations before and after laboratory-based meals (self-reported on visual analogue scales anchored at 0 'Not at all' and 100 'Extremely') | 24 hours after intervention administered | 
| Moderate-vigorous physical activity | Moderate-vigorous physical activity (recorded using wearable activity tracker), operationalised as active minutes/day (logged for activities with a metabolic equivalent of >/3) | 24 hours after intervention administered | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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portion size, socio-economic position, eating behaviour