Your body matches your weight. As in my case, your stomach is bigger. One of the reasons is that you eat and your stomach is full. Therefore, the first thing you have to do is to control your food intake. Don't let your stomach hold up every time, just feel full.

Second, there are two kinds of sit-ups. I'll show you professional pictures and two poses. If you do it, you must stick to it, or you will be hungry when you are finished, and you will eat when you are hungry. Eating it will grow, and practicing it for nothing may be counterproductive.