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Completed

NCT Number: NCT06119295

Investigating the Effects of Altering Portion Size Reduction Awareness on Compensatory Eating Behaviour

The present study aims to investigate whether energy intake is reduced when participants consume a reduced portion size (15% compared to the 'control' portion), and also to see whether awareness of this reduction affects energy intake.

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Key information

Conditions

Eating Behavior Behavior Behavior, Animal Body Weight Feeding Behavior Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Liverpool

Liverpool, L69 7ZA, United Kingdom

About this study

In the present study, all participants will participate in two sessions - the baseline session and the experimental session. In the baseline session, participants will be given ad libitum access to a lunch meal (followed by ad libitum access to dessert), and ad libitum access to a dinner meal (followed by ad libitum access to dessert). Then, after a washout period of between 1-6 weeks, participants will return to complete the experimental session, where they will be randomised to one of three conditions:

Condition 1 (control condition): The same as the baseline condition except that the lunch will be of a fixed portion which participants must consume all of - this portion size will be the same amount of food as was consumed in the ad libitum lunch meal in the baseline session (participants will be told that the amount of food served is the same as the amount they consumed in the baseline session).

Condition 2 (reduced aware condition): The same as the baseline condition except that the lunch will be of a fixed portion which participants must consume all of - this portion size will be 15% less than the amount of food consumed in the ad libitum lunch meal in the baseline session (participants will be told that the amount of food served has been reduced from the amount they consumed in the baseline session).

Condition 3 (reduced unaware condition): The same as the baseline condition except that the lunch will be of a fixed portion which participants must consume all of - this portion size will be 15% less than the amount of food consumed in the ad libitum lunch meal in the baseline session (participants will be told that the amount of food served is the same as the amount they consumed in the baseline session).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • United Kingdom (UK) residents able to visit laboratory on campus in Liverpool, aged ≥ 18
  • Body Mass Index (BMI) between 18.5 and 32.5 kg/m2
  • Proficiency in English language
  • Self-report willingness to eat each of the test foods

Exclusion criteria

  • Current medication use which affects appetite
  • Pregnant
  • Currently or previously diagnosed with an eating disorder
  • Currently on a diet
  • Have any food allergies or intolerances
  • Are vegan

Treatment and study plan

Portion size manipulation

Behavioral

The intervention will be administered via changing portion sizes of foods served to participants. Depending on the condition participants are in, they will be served either a portion size which consists of the amount of food they consumed in the first test session, or a reduced portion size. Within these two reduced portion size conditions, one group of participants will be made aware that their portion size has been reduced, the other will not and instead will be told that this portion size is the same as the amount of food they consumed in the previous session.

Primary outcomes

  1. Immediate energy intake post-fixed lunch meal

    Time frame: Within 30 minutes after intervention administered

    Amount of energy consumed from the lunch dessert

  2. Total delayed post-fixed lunch meal energy intake

    Time frame: Within 10 hours after intervention administered

    Amount of energy consumed from the post-lunch snack box intake, dinner meal, dinner dessert, post-dinner snack box intake, additional energy intake

  3. Total post-fixed lunch meal energy intake

    Time frame: Within 10 hours after intervention administered

    Amount of energy consumed from the lunch dessert, post-lunch snack box intake, dinner meal, dinner dessert, post-dinner snack box intake, additional energy intake

Secondary outcomes

  1. Post-lunch snack box intake

    Time frame: Within 4 hours after intervention administered

    Amount of energy consumed from snack box consumed between lunch and dinner

  2. Total intake of the ad libitum dinner meal

    Time frame: Within 4-5 hours after intervention administered

    Amount of energy consumed from the dinner meal

Sponsors and collaborators

Lead sponsor

University of Liverpool

Other

Registry information

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Nov 7, 2023
Registry last updated
Dec 18, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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