I think it's so dependent on one's unique constitution and family genetics. Some things are probably "bad" though, trans fats, too much sugar, too much sodium and although somewhat controversial, I think too much saturated fat. I follow heart health guidelines via Cleveland Clinic, etc. and most of their thinking is that sat. fats should be limited. I do dairy, but low fat. Don't miss beef, pork or turkey. I eat a little fish and chicken, but could easily ditch it someday. I think certain vitamins, supplements and herbs help our health, too. Other lifestyle factors are equally important in keeping healthy, exercise, stress reduction and paying attention to our emotional /psychological health which impacts our overall health.