A relative newcomer to diet world, the Whole30 program is designed to "help you put an end to unhealthy cravings and habits, restore a healthy metabolism, heal your digestive tract, and balance your immune system." The idea is that for 30 days, dieters strip sugar, grains, dairy and legumes from their diets and eat only meats, eggs, vegetables, some fruits, oils, nuts and seeds. There's no alcohol allowed, but thankfully stepping on a scale during those 30 days also is not allowed because the diet is about more than weight loss.
Program founders Melissa and Dallas Hartwig say this diet will "change your life" by eliminating cravings, resetting your body and changing how you think about food. But the rules are very strict, with even cooking wine, chewing gum and "mock" treats (like coconut milk ice cream) adamantly forbidden. Plus, there has been no independent research to back up the Hartwigs' claims of health benefits. (For example, their website says the diet can fix "aches and pains that can’t be explained by over-use or injury.")
In their 2017 diet rankings, U.S. News and World Report put Whole30 last in their list of 38 diets due to its "extreme" and "restrictive" nature.