To be diagnosed with Bulimia Nervosa, a person needs to display the following behaviors, on average at least once a week, for 3 months:
- ongoing episodes of binge eating. Binge eating is characterized by the amount of food eaten in a 2-hour period that is larger than what most people would eat in similar circumstances. It also involves a lack of control over eating during that episode. The person may feel like they can't stop or control what they are eating.
- ongoing behaviors to prevent weight gain, such as causing one's self to vomit, misusing laxatives, diuretics, or other medications, fasting, or excessive exercise.
The person's self-evaluation must also be overly influenced by their body shape and weight.
The food consumed during binges varies, but typically includes sweet, high-calorie foods. Binging is often characterized by eating very quickly until the individual is uncomfortably or even painfully full. Binge episodes are often surrounded by painful emotions. Before a binging incident, people with bulimia often describe depressed moods, stress, or intense hunger following control over what they have been eating. They try to continue to stay in control and talk themselves into believing that they should not binge. This leads to increasing levels of anxiety. During the binge, there is typically a sense of lack of control and an increase in self-criticism, as well as justification for the behavior. After the binge, many experience shame, guilt and regret.
People with bulimia fear weight gain. They typically believe they must undo or make up for the binge episode. To do this, they purge what they consumed by making themselves vomit. They do not recognize that most of the calories consumed during a binge remain in the body and are not reduced by purging. However, the immediate effects of vomiting include relief from physical discomfort as well as reducing fear about gaining weight. Other purging behaviors include the misuse of laxatives and diuretics (medications that cause you to urinate), as well as excessive exercising. People may also fast (periods of not eating) and skip meals frequently to lose weight. When they do eat meals, they may drink large amounts of fluids, take very small portions, cut food into tiny pieces, or chew their food excessively.
People with bulimia believe that they need to keep their embarrassing behaviors hidden from their friends and family. They may avoid eating meals with others, or make frequent trips to the bathroom during or after meals. They may have an increased desire for privacy in the bathroom or run water to conceal the sound of vomiting. They may also go for unexpected walks or drives at night after meals or go to the kitchen after everyone else is in bed. It is not uncommon for them to chew mints or gum to conceal the smell of vomit on their breath. They might also wear baggy clothing to conceal the size of their body.