Alyssa Mallette Posted over 1 year ago Is diet and exercise a huge oversimplification of obesity? Do we need an unprejudiced reconsideration? When talking about nutrition, a diet may do some good in the beginning; but if the person goes off the diet and resumes their original ways then the diet was useless. It is the lifestyle change, the permanent change that will induce the results. Are you talking about illness in other regards, like thyroid issues, etc?