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Promotion of Exercise and Health in Obesity

Not Applicable
Conditions
Obesity
Interventions
Behavioral: SDT and Motivational Interviewing in Obesity Treatment
Registration Number
NCT00513084
Lead Sponsor
Technical University of Lisbon
Brief 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.

Recruitment & Eligibility

Status
UNKNOWN
Sex
Female
Target Recruitment
259
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 & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
SDT InterventionSDT and Motivational Interviewing in Obesity TreatmentThis arm will follow main experimental intervention, as described elsewhere
Primary Outcome Measures
NameTimeMethod
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 DXAbaseline, 4, 12, 16, 24 and 36 months
Secondary Outcome Measures
NameTimeMethod
Dietary Intake, psychosocial SDT-based mediatorsbaseline, 4, 12,16, 24 and 36 months

Trial Locations

Locations (1)

Faculty of Human Movement, Technical University of Lisbon

🇵🇹

Lisbon, Estrada da Costa, Portugal

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