Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Class |
|---|---|
| European Research Council | OTHER |
Not provided
Not provided
Not provided
Not provided
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).
See attached protocol document.
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Larger portions | Experimental | 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 | Experimental | 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). |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Portion size manipulation | Behavioral | The intervention was administered via changing portion sizes of foods served to participants. |
|
| 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 |
| 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 |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Identify as female
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Eric Robinson, PhD | Study Principle Investigator | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Liverpool | Liverpool | L69 7ZA | United Kingdom |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 37101143 | Derived | Langfield T, Clarke K, Marty L, Jones A, Robinson E. Socioeconomic position and the influence of food portion size on daily energy intake in adult females: two randomized controlled trials. Int J Behav Nutr Phys Act. 2023 Apr 27;20(1):53. doi: 10.1186/s12966-023-01453-x. |
Not provided
| ID | Type | URL | Comment |
|---|---|---|---|
| Study Protocol | View IPD |
Study data (anonymised) will be shared on the Open Science Framework (OSF)
On publication, indefinitely
Open website
Not provided
| Type | Includes Protocol | Includes SAP | Includes ICF | Document Label | Document Date | Document Uploaded Date | Document File Name |
|---|---|---|---|---|---|---|---|
| Prot_SAP | Yes | Yes | No | Study Protocol and Statistical Analysis Plan | Oct 1, 2021 | Oct 27, 2021 | Prot_SAP_000.pdf |
Not provided
| ID | Term |
|---|---|
| D005247 | Feeding Behavior |
| D009765 | Obesity |
| ID | Term |
|---|---|
| D001522 | Behavior, Animal |
| D001519 | Behavior |
| D050177 | Overweight |
| D044343 | Overnutrition |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
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 |
Protocol on the Open Science Framework (OSF) |
| Statistical Analysis Plan | View IPD |
| Individual Participant Data Set | View IPD | The study protocol and statistical analysis plan were pre-registered on the OSF prior to starting recruitment. Participant dataset (anonymised) will be made available when results are published. |
| D009748 |
| Nutrition Disorders |
| D009750 | Nutritional and Metabolic Diseases |
| D001835 | Body Weight |
| D012816 | Signs and Symptoms |
| D013568 | Pathological Conditions, Signs and Symptoms |