I did that, once upon a time... And at 6 feet tall, and not small boned, dropped down to 123lbs. You could see my hip sockets. Not a good look. (I wear a bikini at 160-180lbs). I know a lot of people who do it once totally out of ignorance. If you're not hungry? You don't eat.
Most of us eventually learn to rub 2 brain cells together to get a spark. It's still hard to remember to eat, and we have to be middling careful about what we eat (high calorie & nutrient dense, because we're gonna forget rather frequently... And ideally wet & easy to swallow, because adrenaline cuts the salivary response)... But we do eat. If it's already in the house. I just went out and spent $200 on food yesterday aaaaaaaand that's enough. Couldn't force myself to also cook any of it. Too much work.
Things to keep on hand:
- nutrition shakes
- soups
- high calorie snacks that don't need heating up
- easy foods like cereal & sandwiches & things that go in the microwave
- sugar sugar sugar sugar!!! (The brain runs off pure sugar / glucose. Not only does it help to be able to think, but the brain controls every other bodily response. To this end many years ago I switched almost entirely to soda. It means that no matter how bad off I get, at least my brain has fuel. And if my brain has fuel, I not only feel better, but can think better. Clearly, not diet/ sugar free/Italian soda, etc. Sugar or corn syrup. Literal life saver for me I don't know how many times).