Portion Size Strategies for Management of Body Weight

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Behavioral: Advice on diet, physical activity, and behavior change; Behavioral: Instruction in food portion size; Behavioral: Advice on healthy eating for weight loss; Other: Provision of pre-portioned foods

• Registration Number: NCT01474759
• Lead Sponsor: Penn State University

Brief Summary

The primary aim of this research is to determine the efficacy of two portion-control strategies to achieve sustainable dietary and behavior changes and to promote weight loss and maintenance. A randomized controlled trial will test two approaches to managing portion sizes: one that gives individuals skills and tools to help them make appropriate portion choices, and another that focuses on consumption of pre-portioned foods in order to limit exposure to large portions in the personal food environment. A third group will receive a basic nutritional program to promote weight loss.

The second aim of the research is to determine the effects of the programs on knowledge and consumption of appropriate portions, as assessed by innovative assessment methods and multiple-pass dietary recalls. The third aim is to conduct exploratory analyses of individual factors that may influence the response to the portion-control interventions, such as psychosocial indicators, blood biomarkers, and measures of adherence to the interventions. The expected outcome of the project is that it will lead to the development of specific, evidence-based strategies to help control portion sizes in order to manage weight.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2011-11-15
• Study First Submitted QC: 2011-11-17
• Study First Posted: 2011-11-18
• Study Start: 2012-07
• Primary Completion: 2015-03
• Study Completion: 2015-03
• Status Verified: 2015-05
• Last Update Submitted: 2015-05-14
• Last Update Posted: 2015-05-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 186

Inclusion Criteria

• Body mass index of 28 to 45 kg/m squared
• Able to safely engage in physical activity (walking)
• Able to attend regular instructional sessions at University Park, Pennsylvania

Exclusion Criteria

• have a medical condition diagnosed by a physician that precludes participation
• report symptoms indicative of depression or disordered eating
• report serious food allergies or intolerance
• current or planned participation in a weight-loss program
• pregnant or lactating or planning to become pregnant in the next 18 months

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Portion size instruction	Advice on diet, physical activity, and behavior change	Advice on diet, physical activity, and behavior change. Instruction in food portion size.
Portion size instruction	Instruction in food portion size	Advice on diet, physical activity, and behavior change. Instruction in food portion size.
Pre-portioned foods	Advice on diet, physical activity, and behavior change	Advice on diet, physical activity, and behavior change. Provision of pre-portioned foods.
Comparison	Advice on diet, physical activity, and behavior change	Advice on diet, physical activity, and behavior change. Advice on healthy eating for weight loss.
Comparison	Advice on healthy eating for weight loss	Advice on diet, physical activity, and behavior change. Advice on healthy eating for weight loss.
Pre-portioned foods	Provision of pre-portioned foods	Advice on diet, physical activity, and behavior change. Provision of pre-portioned foods.

Primary Outcome Measures

Name	Time	Method
Change in body weight	Months 0 to 12	Body weight will be measured at multiple time points during the 12-month trial; the main outcome will be the weight trajectory across this time

Secondary Outcome Measures

Name	Time	Method
Change in portion size selection, perception, and knowledge	Months 0, 3, 6, & 12	Computerized assessment of various foods (for self-selected portion sizes, estimation of calorie content, and satiety value) and general knowledge about portion size
Change in portion size consumption	Months 0, 3, 6, & 12	Portion sizes consumed in various food categories as assessed by diet recalls and diet records
Change in blood biomarkers	Months 0, 3, 6, & 12	Fasting lipids, glucose, insulin, and calculated insulin resistance
Change in waist circumference	Months 0, 3, 6, & 12
Change in blood pressure	Months 0, 3, 6, & 12
Change in dietary intakes	Months 0, 3, 6, 9, & 12	Energy intake, nutrient intakes, dietary energy density, food group intakes, and diet quality from three days of 24-hour diet recalls
Change in step counts	Months 0, 3, 6, 9, & 12	Daily step counts from pedometers
Change in attitudes and behaviors related to food and eating	Months 0, 1, 3, 6, & 12	Self-reported eating attitudes and behaviors on multiple questionnaires
Change in psychosocial characteristics	Months 0, 3, 6, & 12	Questionnaires measuring psychosocial characteristics including impulsivity, variety-seeking, and self-efficacy
Intervention adherence	Month 12	Number of sessions attended, number of diet and activity records completed, and frequency of using intervention strategies during the entire trial

Trial Locations

Locations (1)

Penn State University Laboratory for the Study of Human Ingestive Behavior; 🇺🇸 University Park, Pennsylvania, United States