This is taught in nutrition classes, that the gastrointestinal tract, from mouth to anus, is external to the body. What you put into it, or on it, can make you feel good or bad. If you feel bad, look first to what you’re eating:

“When you have these problems [indigestion, cramps, diarrhea], think first of what you put into your intestine. Don’t think you’ve got some stress problem, some psychological problems, some neuroses.”

In the end he gives an example of his diet. (It’s a low-fat vegan diet): “oatmeal for breakfast, minestrone soup for lunch, bean burritos for dinner.” I’ll add things like rice and beans, beans on toast, cold pasta with vegetables, hot pasta with tomato sauce, toasted whole grain English muffins with peanut butter or jam, mashed potatoes, roasted potatoes, baked sweet potatoes, refried beans with cornbread, vegetarian chili. He says, “It’s a simple solution. It’s better than being chronically ill, in pain, and dependent on medication.” I think he’s right.