Previous studies have shown that ghrelin levels are increased prior to access to a palatable food (chocolate) offered for a limited time each day in a schedule feeding paradigm, and that ghrelin is important for the expression of anticipatory hyperlocomotor activity for the palatable food.8 In the present study, we explored how ghrelin could alter food choice during the schedule feed and also total daily energy consumption, both of which are important for obesity development. The gene discussed is GHRL; the disease is obesity due to melanocortin 4 receptor deficiency.