Clinical trial NCT02898844: Randomized Controlled Experiment of Dieting in Pairs
Official title: Randomized Controlled Experiment of Dieting in Pairs
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dietary Modification
Keywords: dieting
dyads
psychological well-being
weight loss
cortisol
Lead sponsor: University of California, Los Angeles
Sponsor class: OTHER
First posted: 2016-09-13
Enrollment: 164
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: This study examined how dieting with a partner affects weight loss, diet adherence, psychological well-being, and cortisol.

Detailed description: The goal of this study was to understand how different types of diet "buddy systems" affect diet success and outcomes related to dieting. Pairs of non-romantic cohabiting female dyads (i.e. roommates) were randomly assigned to one of the following three-week manipulations: (a) neither roommate dieted, (b) one roommate was assigned to a 1200-calorie/day diet and the other ate normally, (c) both roommates were assigned to a 1200-calorie/day diet. Both pre- and post diet, participants were weighted and measured, filled out psychological questionnaires, and provided two days of diurnal salivary cortisol samples. During the three-week manipulation period, participants who were assigned to diet recorded all calories consumed on each day. This study tested whether dieting in a pair would lead to improved diet outcomes in terms of adherence and weight loss, changes in psychological well-being, and changes in cortisol.

Eligibility criteria: Inclusion Criteria:

* Female
* Over 18 years of age
* Interested in dieting in the coming 12 months
* self-reported BMI over 18.5
* \< 5 kg weight change in previous 3 months
* Have a university meal plan
* Have a roommate also willing/eligible to participate

Exclusion Criteria:

* Recent/current history of major medical disorder
* Pregnancy/lactation
* History of eating disorder
* Use of lipid-lowering medications
* Use of weight-altering/metabolism-altering medications
* Smoking

Primary outcomes:
measure: Psychological well-being measured via electronic questionnaires
timeFrame: ~3 days after end of 3-week manipulation
measure: Weight loss measured via pounds
timeFrame: ~3 days after end of 3-week manipulation
measure: Diet adherence measured via daily calorie counts
timeFrame: up to 3-week
Secondary outcomes:
measure: Cortisol measured via 2 days diurnal cortisol
timeFrame: 1 day after end of 3-week manipulation
Other outcomes:
Locations:
Study officials:
affiliation: University of California, Los Angeles
name: A. Janet Tomiyama, PhD
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Cohen S, Kamarck T, Mermelstein R. A global measure of perceived stress. J Health Soc Behav. 1983 Dec;24(4):385-96. No abstract available.