What do you think of people who go on extreme diet just to look slimmer?

In my opinion, going on extreme diet is dangerous and one shouldn\'t even try. I tried going on a diet and communicated with other dieters three years ago. I was impressed by other dieters and thought that I should eat less than a half than I had eaten before. It was not a very extreme diet but my eating habits and the way of thinking about food changed dramatically. I got a tendency to think too much on what I eat. Although I gained muscles, lost some fat and look healthier than before, I got problems with hormones and I sometimes have an impulse to overeat. Unless one is obese, one should think carefully of going on a diet.