Prevalência de comportamentos voltados à perda de peso e suas associações com índice de massa corporal e autopercepção

Abstract

Objectives: The aim of this study was to determine the prevalence of weight control behaviors (WCBs) in a large sample of web-based inquiries of Brazilian nationals and the correlation with body mass index (BMI) and weight-based self-perception. Method: The data were collected by the Brazilian Internet Study on Temperament and Psychopathology (BRAINSTEP) in 27,501 volunteers (30.4% men) with a mean age of 28.9 ± 8.7 years. Results: The most prevalent WCBs for men and women were exhaustive physical exercise and prolonged fasting, respectively (p<0.001). Vomiting, intake of appetite suppressant medications, diuretics and laxatives were 3-8 times more common in women than in men. Frequent exhaustive physical exercise was the only behavior more often adopted by men. BMI was positively associated with WCBs, reaching high frequency in obese subjects (20-30% in male and ~40% of female). About 15% of normal weight women reported using diuretics and laxatives, and 12.2% reported vomiting at least sometimes. The prevalence of frequent WCBs in the thin and very thin groups was lower than in the normal weight group. For subjects whom body weight was highly regarded in their self-perception, there was a strong positive association with all WCBs, at similar degrees, in both genders. Compared to those who never base their intrinsic personal value on body weight, those who do it very frequently have 25-30 times higher risk of inducing vomiting (OR 30.70, 95%CI 9.38-100.49 for men and OR 25.49, 95%CI 17.50-37-13 for women). Conclusion: The prevalence of participants adopting WCBs was high, especially in women and obese subjects. Weight-based self-evaluation was more strongly associated to WCBs than BMI.