Maimonides says that even if you eat healthy foods, don't overeat.
"The tzadik eats to satiate his soul." He knows how much to eat for the soul to remain connected to the body and give it strength.
"Eat to satiation and bless God." "Satiation" in Hebrew is the same as "seven." Eat in sevens (seven bites, one for love, one for fear…).
When you exercise, exercise in sevens as well (seven pushups etc.). "All sevens are beloved." When you reach seven you have reached Shabbat.
To eat is to consume, to become one with you. In Hebrew, the root "eat" reads one-all – one is all (there is) and all (there is) is one.
Chassidim say: "God is all and all is God." When one eats with the consciousness that "God is all…," the physical food sustains the soul.