1062 children at the age of 7 months and their families were randomized 1:1 in an intervention arm and a control arm. The intervention families has received child-oriented and individualized nutritional and life-style counseling that aims at decreasing child's exposure to the known environmental atherosclerosis risk factors. The controls children receive information as given at the well-baby clinics and in school health care of children and adolescents. The hypothesis is that the intervention children have healthier food habits and serum serum lipid and lipoprotein concentrations than the controls, fewer of them start smoking, and their physical activity level is higher than that of the controls. We further hypothesised that the life-style intervention had no adverse mental or somatic effects on the children. Intima-media thickness of the carotid and brachial arterias and aorta and vasodilatation of the brachial artery induced by endogenous NO production have been also been measures at 2-year intervals since the age of 11 years. Recruitment to the study began in 1990 and continued for 2 years. The children are now between 14 and 16 years of age. 550 children remain in the study, which will continue until the last children have reached the age of 20 years.