Abstract: Methods and compositions capable of controlling weight in an animal, preferably a human, which methods involve administering diet compositions that modulate, and preferably reduce, synthesis and secretion of neuropeptide Y (NPY) and modulate, and preferably increase synthesis and secretion of growth hormone releasing factor (GRF), compared to pre-administration amounts in the animal. The administration of such diet compositions results in a reduced appetite and a regulated metabolism that enhance weight control, including weight loss and reduction of obesity.