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OpenTrials
Completed

NCT Number: NCT02898844

Randomized Controlled Experiment of Dieting in Pairs

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

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Key information

Conditions

Dietary Modification Behavior Body Weight Body Weight Changes Pathological Conditions, Signs and Symptoms Personal Satisfaction Psychological Well-Being Signs and Symptoms Weight Loss

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Mixed Diet Condition

Behavioral

One roommate dieted and the other ate normally.

Both Diet Condition

Behavioral

Both roommates dieted.

Primary outcomes

  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 outcomes

  1. Cortisol measured via 2 days diurnal cortisol

    Time frame: 1 day after end of 3-week manipulation

Sponsors and collaborators

Lead sponsor

A. Janet Tomiyama

Other

Registry information

Important dates

Study start
2013
Primary completion
2014
Study completion
2014
First posted
Sep 13, 2016
Registry last updated
Sep 13, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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