Make sure that the diet has been studied extensively for safety — and discuss any changes with your physician or registered dietitian before beginning a new diet. (If you don’t have a dietitian, find one in your area at the Academy of Nutrition and Dietetics website.) And do a self-check to ensure the diet fits with your own values and preferences.
Basically, the effect of exercise on our weight is vastly overrated. That’s why it’s only number 15 on this list. There are other things you need to take care of first. It’s not a good idea to eat bad food, drink sugar water (so-called “sports drinks”) or be on medications which force you to exercise for hours daily just to compensate. Metaphorically that’s like digging a hole, into which you put your ladder, on which you stand and paint the basement-level windows of your house.
Sure, you can lose weight quickly. There are plenty of fad diets that work to shed pounds rapidly -- while leaving you feeling hungry and deprived. But what good is losing weight only to regain it? To keep pounds off permanently, it's best to lose weight slowly. And many experts say you can do that without going on a "diet." Instead, the key is making simple tweaks to your lifestyle.