Selection of subjects studied was based on social learning/cognitive theory, which states that behaviors are a function of personal and environmental factors. The specific aims of the study were as follows: 1) To study the determinants of physical activity and dietary intake of fat, sodium, and calories, and changes in these behaviors in children from ages 4 to 10-11. 2) To determine the relationships between diet and physical activity practices and physiologic indicators of risk, such as blood pressure, adiposity, body mass, and serum lipoproteins at ages 4 to 10-11. 3) To describe the time trends and the degree of tracking of physical activity habits and nutritional intake of fat, sodium, and calories in children from ages 4 to 10-11. The study was renewed in 1999.