The most frequently mentioned eating disorders are bulimia and anorexia nervosa. Yet hyperphagia, binge eating disorder (eating a large amount of food in a very short period of time without subsequent vomiting), craving (eating on impulse a particular food) are also eating disorders that occur around adolescence. It is recognised that these eating disorders are due to both psychological and social environmental factors but also have a genetic component. Often mild APTT is attributed to environmental factors while more severe forms have a high genetic prevalence. For people suffering from anorexia, the desire to lose weight goes far beyond the ideals of health or beauty conveyed today. The desire to be thin is an expression of a serious mental illness. Anorexia causes the sufferer to have an irrational fear of gaining weight, so they impose excessively restrictive diets and strenuous physical exercise, as well as the use of diuretics, laxatives or enemas. A second category of people will have so-called hyperphagic phases, i.e. they will eat large quantities of food in a very short period of time without being able to stop taking food, then in a second phase they will compensate for this action by making themselves vomit or by taking laxatives. These people see themselves as fat even though they weigh far less than normal. This disease can lead to malnutrition and death. As with all eating disorders, emotional and psychological factors have a strong impact on the development of the disease. Bulimia is another serious  eating disorder. In general we speak of bulimic attacks which mean the ingestion of large quantities of food in a limited time. This ingestion compensates for feelings or emotions that the person thinks are insurmountable or a feeling of inner emptiness. The person is unable to stop eating or control what they eat. To counterbalance the crisis and calorie intake, they will implement so-called "compensatory" behaviours that are inappropriate and repetitive such as induced vomiting, the use of diuretics or laxatives, enemas, excessive physical exercise. Food invades the totality of the person’s thoughts which becomes their principal concern in life. They will force themselves to organise their lives around dealing with bulimia. Self-image being very important: the sufferer puts in place strategies to hide these difficulties and project an ideal image of themselves. Failure of control increases the occurrence of bulimia, reducing self-esteem thereby causing even more attacks.