Children of mothers who had diabetes during pregnancy are at an increased risk of diabetes and obesity in later life, effects partly mediated by the early environment experienced by the offspring of diabetic mothers in utero. In this protocol, we address why intra-uterine exposure to maternal diabetes might lead to later childhood obesity. Previous studies of children of diabetic mothers have not detected any alteration in energy expenditure, either as resting metabolic rate or physical activity. We will now examine whether they are at an increased risk of obesity due to differences in food intake. We will assess composition of the diet, patterns of eating, taste preference and physiological responses to a mixed meal. No previous work in human subjects has addressed these issues.