Abstemiousness in diet promotes mental and moral vigor and aids in passion control, while overeating especially harms sluggish temperaments.

Original passage

Abstemiousness in diet is rewarded with mental and moral vigor; it also aids in the control of the passions. Overeating is especially harmful to those who are sluggish in temperament; these should eat sparingly and take plenty of physical exercise. There are men and women of excellent natural ability who do not accomplish half what they might if they would exercise self-control in the denial of appetite.