Longitudinal effects of biopsychosocial variables on physical activity after menarche.

BACKGROUND: The aim of the current study is to analyze the longitudinal effects of certain biopsychosocial variables (socioeconomic status, Body Mass Index (BMI), body image and well-being (QL)), measured at three different menarche stages (S1: before menarche, S2: soon after menarche, and S3: one year after S2), on physical activity and inactivity levels in early adolescence. METHODS: The sample comprised 136 Brazilian teenagers (10-13 years old), showing BMI 18.98 kg/m2 at the initial assessment, who voluntarily participated in the study. Data concerning the following variables were collected in 2010 (S1), 2011 (S2) and 2012 (S3): family income (FI) (socioeconomic anamnesis), BMI (body mass and height), well-being (Autoquestionnaire Qualité de Vie Enfant Imagé) and body image (Body Shape Questionnaire). The physical activity and inactivity levels were measured in S3, only, through the International Physical Activity Questionnaire. The Pearson's correlation and the longitudinal path analysis technique were used to statistically analyze the data. RESULTS: The main results indicated that only family income and BMI, measured soon after menarche (S2), showed significant effect on physical activity and inactivity levels. More specifically, family income has positively influenced (ß=0.25) physical inactivity levels and negatively influenced (ß=-0.14) moderate physical activity levels, whereas BMI has positively influenced (ß=0.15) walking levels and negatively influenced (ß=-0.13) vigorous physical activity levels. CONCLUSIONS: These results suggest that the body image and well-being perceived by the teenagers at different menarche stages are not determining factors of their physical activity levels in early adolescence. On the other hand, the effects of socioeconomic status and BMI on early adolescent girls' physical activity and inactivity levels depend on the assessment period.

Body dissatisfaction and self-esteem in female students aged 9-15: the effects of age, family income, body mass index levels and dance practice.

This study aimed to analyze the effects of age, family income, body mass index and dance practice on levels of body dissatisfaction and self-esteem in female students. The sample consisted of 283 female subjects attending a public school with a mean age of 11.51±1.60 years and a mean body mass index of 18.72 kg/m2 (SD=3.32). The instruments used were the Body Dissatisfaction Scale for Adolescents and the Rosenberg Self-Esteem Scale, both of which showed good internal consistency (0.77 and 0.81, respectively). The tests were applied (two-factor ANOVA) to compare the students practicing and those not practicing dance; the differences in the levels of body dissatisfaction (p=0.104) and self-esteem (p=0.09) were considered significant. The results demonstrated that age negatively correlated with body dissatisfaction (r=-0.19; p<0.01) and that higher body mass index levels were associated with greater body dissatisfaction (r=0.15, p=0.016) and lower levels of self-esteem (r=-0.17, p<0.01) only in non-practitioners. The practice of dance had a significant effect on levels of body dissatisfaction (F=4.79; p=0.030; η(2)=0.02), but there was no significant difference in self-esteem (F=1.88; p=0.172; η(2)=0.02). It can be concluded that female children and adolescents practicing dance have higher self-esteem, and are more satisfied with their body weight and their appearance. Moreover, results showed that self-esteem and body dissatisfaction were influenced by the body mass index levels only in the non-practitioners group.