Excessive gain in body mass index-for-age Z-score and associated factors: a cohort study in female adolescents.

OBJECTIVE: To evaluate the occurrence of excessive gain in body mass index-for-age Z-score (BMI/AZ) and its associated factors in adolescent girls. METHODOLOGY: This is a cohort study conducted between 2007 and 2012 with 382 girls between 10 and 18 years of age attending public schools in Recife, Pernambuco, Brazil. Excessive gain in BMI/AZ (EGBMI/AZ) at follow-up was considered if the adolescent had a BMI/AZ >0.63 between follow-up and baseline. RESULTS: In 2007, 33.5% of girls were overweight, and at the end of the study this prevalence was 26.2%, with no statistically significant differences. Of the 382 girls evaluated in the cohort, 33% showed EGBMI/AZ. In 2007, 95% of these girls were normal weight or underweight, and in 2012, 60% were classified as overweight. After adjusting for possible confounding factors, three variables remained independently associated with EGBMI/AZ: underweight, normal weight and maternal overweight. CONCLUSIONS: Both underweight and normal weight were associated with EGBMI/AZ, and this could be due to a physiological protection for the occurrence of menarche. In fact, maternal overweight has considerable influence on adolescents' nutritional status because of exposure to an obesogenic environment.

Early menarche in normal-weight girls and its association with excess weight, abdominal obesity and metabolic changes at the end of sexual maturation.

BACKGROUND/OBJECTIVES: The objective of this study was to assess whether early menarche in normal-weight girls is associated with excess weight, abdominal obesity and metabolic changes at the end of sexual maturation. SUBJECTS/METHODS: This is a cohort study of 255 normal-weight girls aged 10-18 years attending public schools in the city of Recife, Pernambuco, Northeast of Brazil. The following data were collected in 2007 and 2012: anthropometric; lifestyle, socioeconomic and demographic data; lipid profile; and self-assessed sexual maturation. RESULTS: Eighty-four girls (32.9%) had early menarche. The socioeconomic level and time spent using a computer increased during this 5-year period, whereas the time spent watching television decreased. The prevalences of excess weight and abdominal obesity were 19.2% and 9.8%, respectively. The anthropometric and laboratory variables of girls with and without early menarche did not differ. CONCLUSIONS: These findings suggest that early menarche did not influence weight, abdominal obesity and serum lipids in the final stage of sexual maturation.