SEP and the Impact of Portion Size on Daily Energy Intake

University of Liverpool

Status: Completed

Conditions: Eating Behavior; Obesity; Diet, Healthy

Treatments: Behavioral: Portion size manipulation

Study type: Interventional

Funder types: Other

Identifiers

NCT05173376

803194

Details and patient eligibility

About

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).

Full description

See attached protocol document.

Enrollment: 54 patients

Sex: Female

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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54 participants in 2 patient groups

Larger portions

Experimental group

Description:

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).

Treatment:

Behavioral: Portion size manipulation

Smaller portions

Experimental group

Description:

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).

Treatment:

Behavioral: Portion size manipulation