NCT00513084

Promotion of Exercise and Health in Obesity

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

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 259 (actual)
• Sponsor: Technical University of Lisbon · Academic / Other
• Sex: Female
• Age: 25 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

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.

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.

Conditions

• Obesity

Interventions

Type	Name	Description
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.

Timeline

• Start date: 2004-07-01
• Completion: 2009-07-01
• First posted: 2007-08-08
• Last updated: 2007-08-08

Locations

1 site across 1 country: Portugal