Or you could say he could stop eating altogether. I once stopped eating for a month, survived on water only. Lost a bunch of weight, naturally, looked like a skeleton. Was it good for me, health wise? I'm not sure. Would I recommend it to just anyone? Absolutely not. It could very well do more harm than good.
A month is a bit extreme, but intermittent fasting is exceptionally good for you and the way our bodies were meant to operate. Three or four days is ok every month. It can kickstart your metabolism, and make it easier to lose weight.
Before modern food production, humans didn't eat 3 meals a day, snd food wasn't as plentiful, and it was difficult to come by. I believe it was the British elite who came up with the breakfast, dinner, and supper idea. It was mostly to show off wealth, and to indulge in modern food offerings. Many societies today only eat once or twice a day.
18-24 hours without eating will cause your body to go into ketosis. Your body will start using the fat stored in your cells instead of using the fat from the food you're currently eating. This is why we get fat. We never allow our bodies to use stored fat.
This is also why we lose weight by exercise. When you burn more calories than we take in, we burn a small amount of fat each day.
I once went over 3 months without eating a bite or drinking a sip.

But I was in the hospital on intravenous nutrition.
