SEP and the Impact of Portion Size on Daily Energy Intake

Not Applicable

Completed

• Conditions: Diet, Healthy; Obesity; Eating Behavior
• Interventions: Behavioral: Portion size manipulation

• Registration Number: NCT05173376
• Lead Sponsor: University of Liverpool

Brief Summary

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

See attached protocol document.

Study Timeline

• Study First Submitted: 2021-10-14
• Study Start: 2021-10-25
• Study First Submitted QC: 2021-12-20
• Study First Posted: 2021-12-29
• Primary Completion: 2022-04-07
• Study Completion: 2022-04-07
• Status Verified: 2023-01
• Last Update Submitted: 2023-01-09
• Last Update Posted: 2023-01-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 54

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Larger portions	Portion size manipulation	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).
Smaller portions	Portion size manipulation	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).

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
Moderate-vigorous physical activity	24 hours after intervention administered	Moderate-vigorous physical activity (recorded using wearable activity tracker), operationalised as active minutes/day (logged for activities with a metabolic equivalent of \>/3)
Appetite	24 hours after intervention administered	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')

Trial Locations

Locations (1)

University of Liverpool; 🇬🇧 Liverpool, United Kingdom