Like most psychiatric conditions, there is never one causative factor. Biological factors such as a positive family history of eating disorder, having someone else at home who has an eating disorder, pubertal physical changes triggering body image dissatisfaction are some examples.
Social media itself can also be a possible contributing factor with emphasis on physical appearance, pursuit of thinness, glorification of the slim and lean. With the advent of mobile phone apps, some of which enable counting of calories, tracking the energy expended on exercise, even recommend fat burning diets, it is little wonder that our younger tech-savvy population is picking up ways to lose weight and disordered eating behaviors quite easily these days.
Other possible contributory factors include low self-esteem, history of obesity, examination stress, peer influence and wanting to fit in or be popular amongst friends. Being teased or bullied may also be contributing factors.
Occasionally psychosocial stressors such as family stress, dissolution of a marriage, frequent quarrels between parents and sibling rivalry may also contribute to development of eating disorders.