If you’ve been struggling to lose weight for a long time, it’s likely that at some point the following has happened: you start a new fitness plan, filled to the brim with enthusiasm. You lose some weight, and you feel great. Then your weight loss slows and you get worried. Then it stalls completely, and you feel dejected. You don’t know why it happened, so you try harder. After a few more weeks of weight fluctuations, you give up. Most likely you regain the weight.