The growing prevalence of obesity and associated diseases such as type 2 diabetes is a major health concern, including among children. Epidemiological and animal studies suggest that alterations in the metabolic and hormonal environment during critical periods of development, such as fetal life, is associated with increased risk of obesity, hypertension, and type 2 diabetes in later life. There is general recognition that the developing fetus and neonate is highly susceptible to adverse conditions such as maternal obesity and/or diabetes, as well as perinatal malnutrition. In particular, there is growing evidence that the developmental programming of metabolic systems, including the brain, pancreas, liver, heart and adipose tissue, by the perinatal environment contributes to the global increase in obesity and metabolic diseases observed in modern society. The placenta, which plays a critical role in communication between mother and fetus, is also sensitive to changes in the nutritional environment and thus also contributes to the programming of metabolic disease. This Research Topic will provide a synthesis of recent evidence and concepts concerning the cellular, molecular, and behavioral mechanisms underlying the actions of perinatal hormones (including leptin, insulin, and glucocorticoids) and nutrition in programming the development and organization of metabolic systems that regulate body weight, energy balance, and glucose homeostasis.