Portion Size Effects on Body Weight:Free Living Setting

University of Minnesota (UMN)

Status: Completed

Conditions: Portion Sizes

Treatments: Other: portion size kcal of box lunch

Study type: Interventional

Funder types: Other

Identifiers

NCT01820403

R01DK081714 (U.S. NIH Grant/Contract)

FWA00000312-3

Details and patient eligibility

About

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.

Enrollment: 233 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

233 participants in 4 patient groups

portion size small

Experimental group

Description:

400 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.

Treatment:

Other: portion size kcal of box lunch

portion size medium

Experimental group

Description:

800 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.

Treatment:

Other: portion size kcal of box lunch

portion size large

Experimental group

Description:

1600 kcal box lunch was delivered each weekday to each participant at the worksite for a six month period.

Treatment:

Other: portion size kcal of box lunch

control

No Intervention group

Description:

no box lunch provided to participants.