According to the Circadian cycle: Eat in the day time by 6 to 7 PM when sun is there. Our metabolism is at highest each day between 10 AM to 2 PM. You should aim to intake maximum food in these hours, so that you will get the best benefits of a stronger digestive function. Lunch should be lighter than breakfast, and dinner is supposed to be the lightest. You must eat dinner at least 3 hrs before sleep time.