Childhood overweight and maturational timing in the development of adult overweight and fatness: The Newton Girls Study and its follow-up

Objective. Although several studies have suggested that early menarche is associated with the development of adult overweight, few have accounted for childhood overweight before menarche. Study Design. A 30- year follow- up of the original participants in the Newton Girls Study, a prospective study of development in a cohort of girls followed through menarche, provided data on premenarcheal relative weight and overweight (BMI > 85th percentile), prospectively obtained age at menarche, self- reported adult BMI, overweight (BMI > 25), obesity (BMI > 30) and, for a subset of participants, percentage body fat by dual-energy x-ray absorptiometry. Results. Of the 448 women who participated in the adult follow- up at a mean age of 42.1 years (SD: 0.76 years), 307 had childhood data with which to characterize premenarcheal and menarcheal weight status and age at menarche. After a follow- up of 30.1 years (SD: 1.4 years), reported BMI was 23.4 (4.8), 28% were overweight, and 9% were obese. In multivariate linear and logistic- regression analyses, almost all of the influence on adult weight status was a result of premenarcheal weight status (model R-2 similar to 0.199). Inclusion of a variable to reflect menarcheal timing provided very little additional information (model R-2 = 0.208). Girls who were overweight before menarche were 7.7 times more likely to be overweight as adults (95% confidence interval: 2.3, 25.8), whereas early menarche (at <= 12 years of age) did not elevate risk (odds ratio: 1.3, 95% confidence interval: 0.66, 2.43). A similar pattern of results was observed when percentage body fat in adulthood was evaluated. Conclusions. The apparent influence of early maturation on adult female overweight is largely a result of the influence of elevated relative weight on early maturation. Interventions to prevent and treat overweight should focus on girls before they begin puberty.