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Randomized Controlled Experiment of Dieting in Pairs

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ClinicalTrials.gov Identifier: NCT02898844
Recruitment Status : Completed
First Posted : September 13, 2016
Last Update Posted : September 13, 2016
Sponsor:
Information provided by (Responsible Party):
A. Janet Tomiyama, University of California, Los Angeles

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

Condition or disease Intervention/treatment Phase
Dietary Modification Behavioral: Mixed Diet Condition Behavioral: Both Diet Condition Not Applicable

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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 164 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Randomized Controlled Experiment of Dieting in Pairs
Study Start Date : October 2013
Actual Primary Completion Date : December 2014
Actual Study Completion Date : December 2014

Arm Intervention/treatment
No Intervention: Control Condition
Neither roommate dieted.
Experimental: Mixed Diet Condition
Low-calorie diet: One roommate in each pair was randomly assigned to a 1200-calorie/day diet, while the other roommate was instructed to eat normally.
Behavioral: Mixed Diet Condition
One roommate dieted and the other ate normally.

Experimental: Both Diet Condition
Low-calorie diet: Both roommates in each pair were randomly assigned to a 1200-calorie/day diet.
Behavioral: Both Diet Condition
Both roommates dieted.




Primary Outcome Measures :
  1. Psychological well-being measured via electronic questionnaires [ Time Frame: ~3 days after end of 3-week manipulation ]
  2. Weight loss measured via pounds [ Time Frame: ~3 days after end of 3-week manipulation ]
  3. Diet adherence measured via daily calorie counts [ Time Frame: up to 3-week ]

Secondary Outcome Measures :
  1. Cortisol measured via 2 days diurnal cortisol [ Time Frame: 1 day after end of 3-week manipulation ]


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02898844


Sponsors and Collaborators
A. Janet Tomiyama
Investigators
Principal Investigator: A. Janet Tomiyama, PhD University of California, Los Angeles

Publications:
Spielberger CD, Gorsuch RL, Lushene RE. State-trait anxiety inventory (self-evaluation questionnaire). Consulting Psychologists Press: 1970.
Radloff, L. S. The CES-D scale a self-report depression scale for research in the general population. Applied psychological measurement, 1(3): 385-401, 1977.

Responsible Party: A. Janet Tomiyama, Faculty Sponsor, University of California, Los Angeles
ClinicalTrials.gov Identifier: NCT02898844     History of Changes
Other Study ID Numbers: 13-000666
First Posted: September 13, 2016    Key Record Dates
Last Update Posted: September 13, 2016
Last Verified: September 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Keywords provided by A. Janet Tomiyama, University of California, Los Angeles:
dieting
dyads
psychological well-being
weight loss
cortisol