ONE-YEAR CHANGES IN WEIGHT AND FATNESS IN GIRLS DURING LATE ADOLESCENCE

Objective. To document postmenarcheal growth and changes in weight and fatness in girls. Design. Mixed longitudinal study to determine yearl y growth increments. Participants. Six hundred sixty-eight postmenarch eal girls, initially ages 13 to 17 years, from two Philadelphia high s chools. Overall, 61.4% of the girls were white, 15.7% black, 16.8% Pue rto Rican Hispanic, and 6.1% of other ethnicities (non-Puerto Rican Hi spanic or Asian). Outcome Measures. Height (in centimeters), weight (i n kilograms), and triceps and subscapular skinfold thicknesses (in mil limeters) were measured initially and after 1 year. The anthropometric measures were analyzed both cross-sectionally by age cohort and longi tudinally. Results. Viewed cross-sectionally by chronologic age groups and adjusted for ethnicity, gynecologic age, cigarette smoking, and l ate maturation (menarche greater than or equal to 14 years), there wer e no statistically significant trends with age in height, weight, body mass index (kilograms per m(2)), triceps, or subscapular skinfold thi cknesses. Nevertheless, there were significant trends in velocity with increasing chronologic age. On the average, postmenarcheal girls gain ed about 6.5 kg (14.3 Ib) during late adolescence from about 1.5 years after menarche to age 18 years. Height and triceps skinfolds showed s ignificantly decreasing velocities, whereas there was a significant mo notonic increase in velocity with age for skinfolds at the subscapular site. Conclusions. Even with normal weight gain during late adolescen ce in girls, there seems to be greater potential for fat deposition ce ntrally. Thus, excessive weight gain during late adolescence may exace rbate the normal processes of fat deposition, leading to large gains i n central fat, and thereby increasing the long-term risk for metabolic and cardiovascular diseases later in life.