They're about the same age as my kid, and they're about the same height. So, if I think I know for the time being, I can't say that I'm fat. Even if I say that I'm worried too much, you might say that's not the case; I'm just kidding.
Actually, I try not to gain weight either. I'm currently about 178 or 179 centimeters tall and weigh about 67 kilograms. So I'm not extremely thin, but I'm slender, right? But before, it was about 78 kilograms. My blood pressure got high and I didn't want to take medicine, so I decided to exercise and lose weight. I'm also cutting down on salt. So now my blood pressure is always normal. I want to maintain this state somehow, so I try not to gain weight.
So, just a little bit, but I understand how you feel. After all, I want to stay slender. However, it's not good to be particular about how slender you look. It also seems that there are many people who repeatedly anorexia and overeat for exactly that reason. However, apart from the general element of young women being concerned about how they look, it seems that there are many cases where they are not mentally satisfied. I don't know if that applies to you, but when I read the text of your question, I wonder why you have a sense of scarcity. This is the biggest problem, but your text doesn't directly convey it.
If it's simply for beauty, you can lose weight healthily by eating what you want to eat to a certain extent and exercising a little. Exercising is mentally uplifting and enjoyable, so it's two birds with one stone. But that's probably not a problem. Why do you overeat?
Added after receiving a reply
I think despair and overeating are due to the same cause. How can it not be solved and can it be improved? I wonder what caused it.