I'm a vegan and also can't eat nightshade veggies because of my arthritis, so this diet wouldn't work. Also for anyone wanting to eat like that, you should first check with your doctor. Diets like this is only good if you never eat any other way, because you will just gain it all back plus more.
The best way to eat healthy and lose weight is to become a vegan or vegetarian. All healthy foods that take fat off and keep it off.