Efeito de uma intervenção interdisciplinar baseada no modelo transteórico de mudança de comportamento em adolescentes com sobrepeso ou obesidade

Abstract

This dissertation deals with lifestyle change in overweight or obese adolescents, and used the Transtheoretical Model of Change (TTM) as an intervention approach. At first, a contextualization of the practical execution of the work is presented as well as important theoretical questions that foment the justification of the study. The first theoretical question deals with data on the prevalence and implications of overweight or obesity on the health conditions of adolescents. National public policies of treatment and prevention are presented as existing alternatives and a description of the concepts of the TTM is presented as an intervention alternative. A review of the literature highlights randomized clinical trials aimed at testing non-drug interventions and adolescent adherence to treatment programs. Thus, the main objective of this thesis is to evaluate the effect of an interdisciplinary intervention based on TTM on the motivation to change lifestyle and health conditions of overweight or obese adolescents. To answer this question, a randomized, simple-blind clinical trial was designed. In this study, participated of 135 adolescents with age between 15 and 18; BMI-≥85th percentile. The duration of the interventions was three months. In order to answer the research problems that stemmed from the main objective, the thesis unfolds in five articles. As the main quantitative results, a more expressive magnitude was observed in the percentile BMI (-0.34%; Cohen'sd = 0.23); waist circumference (-4.88%; Cohen'sd = 0.46); readiness to change feeding (16.85%; Cohen'sd = 0.86) and readiness to initiate physical exercise (33.97%, Cohen'sd = 0.92); of the experimental group compared to control. The dropout rate was 48.8%, with a higher dropout rate explained by low self-efficacy to modify lifestyle (OR: 0.732; 95% CI: 0.581 - 0.921; p = 0.008), low family support (OR: 0.807; 95% CI: 0.685 - 0.950; p = 0.010) and by factors related to parental feeding practices. MTT is an intervention modality disseminated by the brazilian Ministry of Health in the fight against smoking, and results of studies such as this thesis, may contribute to the use of interventions in the public health network for the prevention and treatment of obesity in adolescence.