I want to draw attention to an important psychological problem, named eating disorders.

Eating disorder (ED) is first of all dissatisfaction with and hate of one's body, the division of foods into good/bad, as well as obsessive thoughts about food and a vicious circle of dieting-disruption. 

A huge number of people live with this disorder all their lives and have no idea that it is possible to correct this condition, to love your body and accept it.

Why does ED appear?
According to recent research, there is no single cause. One thing is clear: it's usually a combination of factors - hereditary predisposition (the stomach is home to microorganisms that tend to disrupt eating behavior), an unfavorable family environment, and cultural standard pressures. This means it's not your fault if this happens to you, there's nothing wrong with you.

Regarding cultural standards:

Curiously enough, before the year 2000, no one had any idea about eating disorders, all because the standards of beauty were completely different. If you allow me to go deeper into history, thinness was always considered a bad sign and a sign of poverty, so a healthy body had appropriate roundness. The reasons for eating disorders in the Middle Ages were far from modern times: a desire for spiritual purity instead of a desire for thinness (Christianity).

Cultural standards imposed an ideal of beauty and health, which appears to be thin, although this is far from the case. It has been scientifically proven that people who have enough fat in their bodies live much longer on average. This can be explained by the fact that fats in the body perform many important functions, among which are immunity maintenance, protection, metabolism regulation.

Why don't diets work?
It is a burning question that needs to be answered, because when someone is on a diet and then ignore it, they don't understand why they don't have the willpower to go on with their diet. So, it is physically impossible to stay on a diet, that is, to limit yourself all the time.

Our psyche is organized so that restrictions give rise to breakdowns, and the more you restrain your impulses to eat "forbidden" products, the stronger the internal tension and desire to give up.

The body likes stability. But diets, more often than not, become stressful because of sudden significant changes. In this stress and lack of energy due to too much caloric deficit or too much exercise, the body prioritizes and gets rid of some less important processes for survival.
All this is perceived by the body as a danger to survival and therefore it will try to store up energy at first, because there is a risk of another shortage. Thus, the end of the diet will become a weight gain as an escape for an organism scared of the risk of death.

So what really works?
- Building "a good relationship" with food. In the long run, a healthy relationship with food is the only sure way to keep yourself fit and healthy. Becoming more aware of your desires, removing inhibitions and labels about food, and working through limiting beliefs about food will be the conduit to a healthy image and perception of yourself.

I recommend reading the book "Intuitive Eating" by Svetlana Bronnikova, a well-known psychotherapist in the field of eating disorders, if you want to understand the subject in more detail. This is a workbook that is designed to help you understand the psychology of the disorder and begin the journey of healing.
Also, if you feel that "all is not right," that you are not coping, you can always seek help from a proven professional. You can find a good psychologist at the online psychologist matching service.