Influence of exercise in the body image of preadolescents and adolescents: importance of the body mass index as a factor of confusion

Introduction: adolescents are the group most vulnerable to distortions in the perception of their image. This often leads to body dissatisfaction that can negatively affect their self-esteem. The practice of physical activity (PA) could help solve this problem. Objectives: to analyze the influence that the amount of PA performed has on the self-perception of body image in the pre and adolescent population while taking into account confounding factors that could affect this relationship. Methods: a cross-sectional study of 822 participants aged 9 to 16 years was conducted. The prevalence of PA, their body mass index (BMI), and their objective and perceived physical condition (PC) were determined. The Stunkard pictogram was used to determine the degree of body dissatisfaction. Results: a generalized satisfaction with own body image was found regardless of age and sex. Low-magnitude significant associations were found between perceived body image and the amount of PA, perceived PC, and objective PC. PA did not influence body satisfaction when adjusted for BMI, which was the variable that presented the highest correlations with self-perception (r = 0.713) and self-satisfaction (r = 0.576). Conclusions: a generalized satisfaction with one's own body image was identified in the pre and adolescent population under study. The amount of PA was not shown to be a variable with great influence on self-perception and body satisfaction, contrary to BMI.