There are various contributory causes of eating disorders and often several of these may act in combination.

• The ability to distinguish between hunger, satisfaction and other feelings is learned when one is very young. More. Faulty upbringing can interfere with this. The effect is often not noticed until later in life. More.
• Eating disorders often arise when a person tries to reduce to an abnormally low weight. The unnatural slim ideal may therefore be a contributory cause of eating disorders. More.
• Many people with eating disorders are not aware of their physical feelings of hunger and satisfaction. Thus, they lack a natural control of their eating. Such people will easier be pulled into eating disorders, where they use eating to conceal feelings and escape from constructive problem solutions. More.
• Both overeating and fasting can stimulate the reward centre in the brain. Eating disorders therefore function in the same way as alcoholism and drug addiction. The same personality traits which increase the risk of alcoholism and drug addiction also increase the risk of eating disorders. More.
• The personality traits which increase the risk of eating disorders are partly hereditary. Addictive problems or affective disorders (depression, etc.) are more common among relatives. More.
• Some of the personality traits involved are: a tendency to please others and a low ability to assert one's own needs; a need to reduce unsettling feelings of anxiety, depression and low self-confidence; perfectionism and problems with impulse control. More about personality.
• Eating disorders are more common among women and those who are affected by social attitudes and body ideals and who also lack the ability of following their own feelings and needs. More.
• Children of overweight parents, and parents with an exaggerated interest in body shape, more often get eating disorders. Also, demands from the family and insecure family circumstances increase the risk.

Both biological (somatic) and life-style factors play a role in causing overweight. Eating disorders (see above) can also cause overweight. More. There are also some illnesses and drugs which can make a person more susceptible to overweight. More.