Promotion of Exercise and Health in Obesity (PESO)

August 7, 2007 updated by: Technical University of Lisbon

Moderators and Mediators of Physical Activity, Body Weight, and Body Composition Change During Obesity Treatment in Women

The primary objectives of this randomized clinical trial are a) to implement and test the impact of a 1-year lifestyle obesity treatment program based on Self-Determination Theory on 3-year change in physical activity and motivation for exercise/physical activity, body weight and fat, and selected eating variables, b) to identify behavioral and psychosocial theory-based moderators or mediators of primary outcomes, especially physical activity and body weight.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Obesity and sedentary lifestyles are worldwide threats to public health but feasible and effective strategies to tackle these problems are scarce. The identification of variables that explain why only a sub-group of overweight persons succeeds at increasing physical activity and achieving long-term weight control is a key research topic in exercise and sports sciences. Subjects are 260 healthy women (BMI, 25 to 40 kg/m2), aged between 25 and 50 years, premenopausal, of whom half receive the treatment intervention, the remaining being randomly assigned to a control group at baseline. This RCT consists of a 1-year intervention plus a 2-year no contact follow-up period. The intervention group attended 30 weekly group sessions, designed to follow SDT basic tenets, covering PA, eating/nutrition, body image, and other cognitive and behavioral contents. Central to the intervention model are autonomy, intrinsic motivation, and self-regulation of behavior change. Autonomy-supportive treatment climate and internal causality orientations are predicted to enhance autonomous regulation, perceived competence, and intrinsic motivation for the targeted behaviors, resulting in lasting behavioral and body weight changes. The intervention was designed to follow SDT, with an emphasis on promoting intrinsic, self-regulated motivation for exercise and weight control. The control group received a general health education curriculum based on several 3- to 6-week long educational topics (e.g. food safety, stress management, self-care, body image, and others). Results are expected to contribute to a better understanding of how individual characteristics, particularly those related to physical activity and exercise influence success, better screening/readiness testing procedures, improved matching of interventions to participants, and lower rates of attrition and unsuccessful weight loss attempts.

Study Type

Interventional

Enrollment (Actual)

259

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Portugal
    • Estrada da Costa
      • Lisbon, Estrada da Costa, Portugal, 1495-688 Cruz-Quebrada
        • Faculty of Human Movement, Technical University of Lisbon

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

25 years to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • female (25-50 years old)
  • pre-menopausal
  • BMI between 25 and 40 kg/m2
  • willing to attend weekly meetings (during 1 year)
  • willing to not participate in other formal or informal weight loss program during the first year of the study (intervention group only).

Exclusion Criteria:

  • major/chronic illness
  • taking (or having taken in the previous year) medication known to interfere with body weight regulation, including anti-depressive medication

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SDT Intervention
This arm will follow main experimental intervention, as described elsewhere
Behavioral: SDT and Motivational Interviewing in Obesity Treatment
Thirty group sessions, designed to follow SDT, covering PA, eating/nutrition, body image, and other cognitive-behavioral contents. Central to the intervention are improving autonomy, intrinsic motivation, and self-regulation of behavior change. Accepting ambivalence for change, rolling with resistance, and developing discrepancy were used throughout the program, with an emphasis on promoting intrinsic, self-regulated motivation for exercise and weight control.
Other Names:
  • GI: Intervention Group
No Intervention: Comparison Group
Comparison Group receiving standard care health promotion intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Primary outcomes are physical activity/exercise and body weight/ composition. Physical activity is assessed by accelerometry and standardized interview/questionnaire methods. Body composition is assessed by DXA
Time Frame: baseline, 4, 12, 16, 24 and 36 months
baseline, 4, 12, 16, 24 and 36 months

Secondary Outcome Measures

Outcome Measure
Time Frame
Dietary Intake, psychosocial SDT-based mediators
Time Frame: baseline, 4, 12,16, 24 and 36 months
baseline, 4, 12,16, 24 and 36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Technical University of Lisbon

Investigators

  • Principal Investigator: Pedro J Teixeira, PhD, Faculty of Human Movement, Technical University of Lisbon
  • Principal Investigator: Luis B Sardinha, PhD, Faculty of Human Movement, Technical University of Lisbon

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2004

Study Completion (Anticipated)

July 1, 2009

Study Registration Dates

First Submitted

August 7, 2007

First Submitted That Met QC Criteria

August 7, 2007

First Posted (Estimate)

August 8, 2007

Study Record Updates

Last Update Posted (Estimate)

August 8, 2007

Last Update Submitted That Met QC Criteria

August 7, 2007

Last Verified

July 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FCT-POCI/DES/57705/2004

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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