This prospective, longitudinal study collected data on the twelve cohorts of families. Blood pressures, resting pulse, height, weight, skinfolds, plasma cholesterol fractions and Type A behavior data were collected on the children at five times over the course of five years. During the four years between each of the clinic measurements, observational data were collected on the diet and exercise habits of the children. At the time of clinic assessment, clinic data were also collected on the parents of the children and self report data on the parents' diet, exercise habits, and other psychosocial variables. Two substudies were also conducted. The first assessed energy expenditure levels of children in the three age groups of 3-4 years, 5-6 years, and 7-8 years and the three body types of lean, average, and obese in 12 different activities. The second substudy assessed the accuracy of mothers' 24-hour recall of the diet and exercise behaviors of their 3-4 year old children as compared to observational data on the same behaviors.