Portion Size Effects on Body Weight:Free Living Setting

Portion Size Effects on Body Weight: Free Living Setting

The study purpose was to evaluate the effects of portion sizes on body weight and energy intake in a free-living setting. 223 healthy adults were recruited from an urban worksite and randomized to one of four groups for a six-month period. The groups were: 1) 400 kcal box lunch; 2) 800 kcal box lunch; 3) 1600 kcal box lunch; or 4) no box lunch. Participants were required to pick up a box lunch every week day for six months. Control participants did not receive a box lunch and were instructed to eat their usual lunch. Participants were weighed and dietary intake measured at baseline, one, three and six months. It was hypothesized that at six months, participants in the 1600 kcal box lunch would gain more weight and have higher energy intake than those in the other groups.

Study Overview

• Status: Completed
• Conditions: Portion Sizes
• Intervention / Treatment: Other: portion size kcal of box lunch

• Study Type: Interventional
• Enrollment (Actual): 233
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55454
      • University of Minnesota

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• : 1) age 18-60 yrs; 2) nonsmoker; 3) fluent in English; 4) not taking medications that affect appetite or body weight; 5) work at the medical complex full time, including during the lunch hours; 6) not allergic to the foods in the study lunches; 7) willing to eat the foods in the study lunches [examples were provided of the types of foods]; 8) not currently on a diet to lose weight; 9) no history of a diagnosed eating disorder; 10) not moving from the area during the next six months; 11) not currently taking part in another research study; 12) not currently pregnant, nursing or pregnant in the last 12 months.

Exclusion Criteria: if the person does not meet the criteria above

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Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: portion size small; 400 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.	Other: portion size kcal of box lunch; Other Names: box lunches of different portion sizes were provided to participants each weekday for six months. Portion size conditions were 440 kcal, 800 kcal or 1600 kcal.
Experimental: portion size medium; 800 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.	Other: portion size kcal of box lunch; Other Names: box lunches of different portion sizes were provided to participants each weekday for six months. Portion size conditions were 440 kcal, 800 kcal or 1600 kcal.
Experimental: portion size large; 1600 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.	Other: portion size kcal of box lunch; Other Names: box lunches of different portion sizes were provided to participants each weekday for six months. Portion size conditions were 440 kcal, 800 kcal or 1600 kcal.
No Intervention: control; no box lunch provided to participants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
body weight change	change in body weight from baseline to six months	six months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
dietary energy intake	change in energy intake from baseline to six months	six months

Collaborators and Investigators

• Sponsor: University of Minnesota

Study record dates

Study Major Dates

• Study Start: September 1, 2010
• Primary Completion (Actual): February 1, 2013
• Study Completion (Actual): February 1, 2013

Study Registration Dates

• First Submitted: March 25, 2013
• First Submitted That Met QC Criteria: March 25, 2013
• First Posted (Estimate): March 28, 2013

Study Record Updates

• Last Update Posted (Actual): November 1, 2019
• Last Update Submitted That Met QC Criteria: October 30, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight
• Other Study ID Numbers: FWA00000312-3; R01DK081714 (U.S. NIH Grant/Contract)