The digestive process is strongest in the morning after a night’s sleep. That is why breakfast is a very important meal of the day. It is good to have some protein for breakfast too, as it helps sustain energy and cut down the need for snacking between meals.
The digestion is slowest or weakest at night: hence, best to avoid heavy meals for dinner. Also best to avoid late night snacking.
Cold foods and drinks slow down digestion. Digestion works like a fire that cooks food. If you cool the fire, the food stops cooking. Therefore, contrary to popular belief, too many raw salads and cold smoothies can harm the digestive process. The best foods are lightly cooked or baked vegetables, grains, proteins and some fruits and nuts, as well as some raw salads (especially in warmer or hot climates).
If someone is lacking energy and feels cold all the time, they need to avoid cold foods like cucumbers, watermelon etc.
If someone is too hot they need cooler foods.
It is all about balance. Each person is different.
But in general, remember to eat a healthy breakfast, and remember to eat cooked vegetables and greens as much as possible.
Meat is actually beneficial, in small quantities, for people who are lacking energy and feel weak, or who have diarrhea a lot and loose stools. Red meat is preferable to chicken for that purpose.
This is part of the Chinese medicine which actually is said to have originated from Avraham Avinu. He had six sons from his second wife, Hagar, and he sent them to the east and gave them gifts (taught them healing knowledge, such as acupuncture, herbs and so on).