I agree, many foods are likely to cause many people many problems. I have eliminated most dairy products but do backslide now and then and my stiff, achy knees and hands tell me about it. Food sensitivities, not true allergies, caused severe behavioral problems with my son. He couldn't have dairy products, tomatoes, eggs, peanuts, or chicken. He eats them now and pays the price.
Happiness is catching that dropped stitch while it's still fixable..