3. You Don’t Learn Anything New

Let’s get back to that “lifestyle” point in item 1.

In order for a diet to work long-term, you have to learn what you’re doing wrong now, so you can fix it, and move on to your new, healthier lifestyle.

Fad diets don’t teach you anything new (except, perhaps, that there are literally hundreds of ways to prepare and enjoy a grapefruit), which is another important reasons fad diets don’t work.

There’s No Exercise Involved