Don't try at ordinary times, stay up late on Friday night, then go to bed at 7: 00 in the morning, stay up all day, sleep around 1, get up, stay up for about 6 hours, drink water after getting up, don't eat at night, don't eat around 6: 00, walk to eat, and then come back and find a place at a distance of 10 minutes without eating.
Then drink water, don't eat snacks, and then stay up until 7 o'clock the next morning. The process is exactly the same. If you touch your waistline on Sunday night, it will be much smaller.
Usually you are the same as usual, but you should exercise more and run more. You can try it at the weekend.
The above is only valid for my own attempt. Others can't guarantee that you can try it for a day. If you don't think your stomach is getting smaller, don't try.