Stick to it every day, about 5 minutes each time, and rest for 5 minutes 15 minutes. Stick to it for a week and you will see the effect. However, if you don't completely lose the fat on your stomach, you won't do it, and your stomach will grow back. Don't listen to people say that you don't eat dinner or use something else instead. You're still hungry. Although there seems to be less meat on your stomach, there isn't.

But it is still useful to eat less every day than before.

Sit-ups should be done seriously, because they are not good for the lumbar spine. You can use a belly roll instead. It's similar to sit-ups, but don't sit up when you get up, just lift it a little more than 5 cm from the ground, and don't touch the ground when you go down, and keep it off the ground. At first, you can do four groups in groups of 20, and then gradually increase with the strength of abdominal muscles.