An eating disorder involves an abnormal relationship with food — either eating less or over-eating —with negative effects on one’s physical or mental health 
The most well-known eating disorders are anorexia nervosa and bulimia nervosa. They both include behaviours such as laxative use, self-induced vomiting and over-exercising. Both involve an excessive desire to be thin, but where an anorexic will dramatically cut their calorie intake to the point of starvation, bulimia usually involves a cycle of binge-eating and vomiting 
Binge-eating disorder is characterised by eating more frequently and/or in much larger portions than is normal or healthy, inevitably causing obesity and serious health risks.
How can I help you?
Eating disorders are complex, and treating them involves the development of a comprehensive plan that involves psychological support, psychological interventions, nutritional counseling, and, when necessary, medical care and monitoring. People with eating disorders often do not recognize or admit that they are ill. As a result, they may strongly resist getting and staying in treatment. Family members and trusted friends can be helpful in ensuring that the person with an eating disorder receives needed treatment and support.
A person who is overweight or obese can be helped to return to a healthy eating pattern and a healthy weight. Treatment may utilize behavioral and cognitive therapy as well as nutritional counseling and weight management strategies. The use of medications and careful monitoring is often valuable.
Treatment of anorexia requires a specific program that involves restoring weight that has been lost to severe dieting and purging, treating any psychological disturbances, such as distortion of body image, low self-esteem, and interpersonal or emotional conflicts, and achieving long-term remission and rehabilitation. For patients who have had severe weight loss, initial treatment is often in an inpatient hospital setting. Once the malnutrition has been addressed, and weight gain begins, psychotherapy (often cognitive-behavioral or one-on-one and group psychotherapy) can help people with anorexia overcome low self-esteem and address distorted thought and behavior patterns.
The primary goal when treating bulimia is to cut down on, or even eliminate, the binge eating and purging. Treatment, therefore, involves nutritional counseling, psychological support, and medication management. Patients establish a pattern of eating regular, non-binge meals, and therapy focuses on improvement attitudes related to the eating disorder, encouragement of healthy but not excessive exercise, and resolution of other conditions such as mood or anxiety disorders.  Antidepressants have been found helpful for people with bulimia, especially those who have depression or anxiety, or who don't respond to therapy alone.
The treatment goals and strategies for binge-eating are similar to those for bulimia, and studies are currently evaluating the effectiveness of various interventions.