First of all, you should change your eating habits. Don't sit down or sleep on your stomach immediately after eating. It's best to stand all the time. You can choose to take a walk or pack your things. This can not only reduce fat accumulation, but also help digestion, because within 30 minutes after eating, if you don't move, it is most likely to form abdominal fat.
Suggestion: Finally, we should cooperate with sports. Climbing the stairs slowly every day is the most effective way, especially the thighs, buttocks, abdomen and waist.