Compensation for Smaller Portion Sizes and Portion Size Normality

Compensation for Smaller Portion Sizes and Portion Size Normality: Two Laboratory

Reducing food portion size is a potential strategy to reduce energy intake. However it is unclear at what point consumers compensate for reductions in portion size by increasing energy intake from other items. The investigators tested the hypothesis that reductions to food portion size will only result in significant compensatory eating when the reduced portion size is no longer visually perceived as 'normal'. In two within-subjects experiments, participants (Study 1: N = 45, M BMI = 26.9; Study 2: N = 37, M BMI = 26.9; 51% female) were served different sized portions of a lunchtime meal on three occasions: a 'large-normal', a 'small-normal', and a 'smaller than normal' portion. Both the reduction from 'large-normal' to 'small-normal' and from 'small-normal' to 'smaller than normal' portions represented the same change in food volume and energy content (84g, 77kcal Study 1; 98g, 117kcal Study 2). Participants were able to serve themselves additional helpings of the same food (Study 1), or dessert items (Study 2).

Study Overview

• Status: Completed
• Conditions: Portion Size
• Intervention / Treatment: Behavioral: portion size

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Merseyside
    • Liverpool, Merseyside, United Kingdom, L69 7ZA
      • Ashleigh Haynes

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• general liking and willingness to consume the test foods in each study

Exclusion Criteria:

• food allergies, intolerances or specific dietary requirements (including being vegetarian or vegan)
• a history of eating disorders;

Study Plan

How is the study designed?

Design Details

• Primary Purpose: PREVENTION
• Interventional Model: CROSSOVER
• Masking: NONE

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Meal energy intake	Energy intake from the served portion	Immediate
'Compensatory' (additional) energy intake	Energy intake from additional food provided for consumption after the portion-manipulated meal	Immediate

Collaborators and Investigators

• Sponsor: University of Liverpool
• Collaborators: Medical Research Council

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 4, 2016
• Primary Completion (ACTUAL): July 25, 2017
• Study Completion (ACTUAL): July 25, 2017

Study Registration Dates

• First Submitted: November 2, 2018
• First Submitted That Met QC Criteria: November 5, 2018
• First Posted (ACTUAL): November 6, 2018

Study Record Updates

• Last Update Posted (ACTUAL): November 6, 2018
• Last Update Submitted That Met QC Criteria: November 5, 2018
• Last Verified: November 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: Portion size normality

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD is available on the Open Science Framework https://osf.io/txf9u/

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No