Yes, you must pay attention to a reasonable diet to reduce fat. You can skip dinner, or eat less, and eat more things rich in dietary fiber and low in calories. This will be of great help to you to reduce fat. Besides dinner, try to avoid some high-calorie foods at other times. Do sit-ups, push-ups, suggest from weak to strong, for example, you can do 10 now and you will be exhausted 10 days later, do 20, and then do 30 after 20 days, and so on.