Why do people go on diet?

Nowadays people want to look healthy and slim. They think that it will help them in their career and private life. Especially woman try to lose their weight. They usually take slimming pills and go on exhausting diets. They do that because they want to be admired by men and they want to look like well-known actresses, models and TV announcers. But they have to remember that there are some extreme cases when diet leads to serious disorders and illnesses, for example bulimia and anorexia.
Of course there are some safe ways of losing your weight and looking good. First of all you have to limit proteins and fats, and you must remember to drink a lot, because if you don't, you will dewater your body. You should also remember about exercising because it speeds up metabolism and builds muscles. A good idea is to make a list of things you eat and to count calories.
But we have to also remember that there are a some people who go on diet because they want to feel better or they don't eat some kinds of food because of their convictions and religion. For example Jews don't eat pork, and vegetarians and vegans don't eat any kind of meat.