The answer might surprise you, but it's not breakfast. The best time to eat your main meal of the day is at a time when you can rest afterward, assuming, of course, that you are hungry. We had our m
ain meal at lunch in Greece, but we got a three-hour break later to relax and take a nap. I strongly believe the main meal in America should be eaten in the evening after work because we don't have leisure time during the day like they do in Greece.
Here's why it's important to rest after a large meal. Emotions and moods greatly influence the secretion of digestive juices. People in a good mood have better secretion of digestive juices. Negative emotions like worry, fear, anger, etc., all influence digestion in a wrong way. They stop the secretion of digestive juices, the stomach's rhythmic motions, and the secretion of saliva.
Another factor that affects digestion is the availability of blood. For digestion to proceed normally, blood has to rush to the digestive organs in large quantities. For that to happen, blood vessels that supply organs not essential to digestion constrict to force blood to the organs required for digestion. If, after a large meal, you go right to work (be it physical or mental), your brain and muscles will also need blood to function correctly. That means the blood vessels supplying the brain and muscles will not constrict, so additional blood will not rush to the digestive organs to help digestion. Therefore, digestion gets compromised.
Have you noticed how you feel after eating a large meal? Don't you feel like taking a nap? Well, that's normal. Most of your energy has to go toward digesting the food you just ate. That is why there is a long break after eating in all the cultures in which people eat their main meal at lunch. Since those of us in America can't take long lunch breaks complete with a nap, the best thing to do is eat a very light lunch (only if you are hungry, of course) and eat our main meal at night, when the full attention of the body can go toward digestion.
Look at animals in nature. After a lion eats, it rests; it doesn't run around. Animals instinctively know what to do. Humans, unfortunately, have lost that instinct, but we can get it back by paying closer attention to our bodies.
The only reason breakfast has become the most important meal is because of smart marketing.