A study at Harvard of 5865 girls and 4322 boys between 9 and 14 years old, showed that those who slimmed had a significantly greater chance of becoming overweight or getting eating disorders.
It has been noticed, since the ‘60s, that a strict diet that causes a 25% weight loss in a few months can induce in healthy male volunteers, all the physiological and behavioural changes that we find in eating disorders.
The same phenomenon is found in the animal world. Birds who have starved because of food shortages may later, when there is plenty to eat, become fatter than those birds who had continuous free access to food.
Currently, the frequency of dieting has reached vast proportions in the European population: it is difficult to find a woman, and more and more frequently a man, who can affirm that they have never really followed a diet.
It is also true, especially among women, that a lot of people live regularly interchanging dieting periods, with sometimes very strict and normal eating periods. Therefore, since a lot of people follow strict diets, why does only 5% of the population suffer from a clinically manifest eating disorder?
The answer is that dieting is not enough to cause an eating disorder.
The presence of different biological, social and family factors is necessary to develop an eating disorder. There must be a psychological vulnerability that has the consequence that only some people, who are the ones with particular psychological features, that really risk developing an eating disorder, that, according to the subject’s personality traits, could be of one type rather than another.