Healthy Growth: Project Description and Baseline Findings

Objectives: The purpose of the study was to describe the physical activity, blood pressure, and body fat patterns of sixth-grade, African-American girls (N=82), who participated in the Healthy Growth Study. The purpose of the primary study questions was to determine which sets of variables best predict blood pressure, physical activity, and body fat. Design and Methods: This paper is a cross sectional analysis of the first assessment of a 5-year longitudinal project. Standard procedures were used to assess height, weight, skinfolds, blood pressure, physical activity, predictors of physical activity, maturation, dietary intake, fitness level, and health behaviors. Results: The average age of the subjects was 12.3 years; almost two-thirds of the girls had reached menarche. Fifty-two percent of the 13-year-olds had body mass index (BMI) values greater than the 85th percentile for their age and sex compared to 32% of the 12-year-olds. None of the variables were significantly related to diastolic or systolic blood pressure. Physical activity was significantly and negatively related to total percent of calories from fat and to breast stages and positively related to waist/thigh ratio. Body mass index (BMI) was significantly and positively related to breast stages. Conclusions: Important developmental differences between 12- and 13-year-olds were evident. Body mass index (BMI) was mainly dependent on physical maturity. No relationship was found between BMI and blood pressure. The relationship between physical activity and waist/thigh ratio merits further study. The importance of BMI and physical inactivity as potential indicators of cardiovascular risk in adolescent girls is discussed. Developmentally appropriate and culturally competent interventions are recommended to increase physical activity and healthy eating behaviors among adolescents.