Diabulimia refers to an eating disorder in which Type 1 diabetes sufferers omit their insulin injections for the purpose of weight loss.

Failure to administer insulin places the body in a starvation state, resulting in breakdown of muscle and fat into ketone bodies and subsequently ketoacids. This typically results in significant weight loss but also places the patient at risk of a life-threatening condition known as diabetic ketoacidosis. Prolonged failure to administer insulin results in long-term complications such as diabetic neuropathy.

Following a diagnosis of Type 1 diabetes, a patient is put on insulin injections, a more controlled diet, and several blood sugar checks a day. This may result in weight gain, which some (particularly teen girls) may find embarrassing. This may lead them to neglect their insulin treatment for the purposes of returning to their former weight.

Often, people with Type 1 diabetes who omit insulin injections will have already been diagnosed with an eating disorder such as anorexia nervosa, bulimia nervosa and/or compulsive eating. In cases where a person with Type 1 diabetes has another eating disorder, there is a tendency to discuss the other eating disorders more openly than they do about diabulimia as many people with diabetes are not happy that they have lost control of their diabetes. These individuals are often not aware that diabulimia is more common than what they think and is also very difficult to overcome. Unlike anorexia and bulimia, diabulimia only sometimes requires the afflicted individual to stop caring for a medical condition. Unlike vomiting or starving, there is sometimes no action or willpower involved. Diabulimia may be more appealing to individuals who want to lose weight and do not want to feel hungry, or to not engage in vomiting in order to purge. Often there is an obsessive compulsive urge to engage in this activity for the purpose of emotional disassociation or a need to satisfy feelings of 'control'.

This condition can be triggered or exacerbated by the need for constant vigilance in regard to food, weight and glycemic control. In adolescents the need for parental control over the young Diabetic's life, and the increased weight gain that insulin treatment can cause, may play roles in the increased risk for onset of Anorexia and/or Bulimia. The frustration of managing blood sugars and their subsequent effects on weight and self perception (altered by dealing with a chronic illness) can also be damaging to self esteem and body image.

A person with diabulimia, especially if not caught and treated early, is likely to suffer the extent of diabetes earlier than a person with diabetes who is maintaining their diabetes in a healthy manner. The extent of diabetes includes renal failure, blindness and diabetic neuropathy. With diabulimia there is an increased chance of fatality. Diabetic ketoacidosis (DKA) is very common in persons with Type 1 diabetes that have diabulimia. This is due to the reduction in the amount of insulin and an increase in blood sugars levels. DKA is a very serious condition that occurs without enough insulin and without treatment causes death.

Most commonly Diabulimia appears to start in adolescence and is more likely to occur in women than men. Diabulimia can be identified in a patient if there are unexplainable spikes in their Hemaglobin A1c, weight loss, lack of marks from finger sticks, lack of prescription refills for diabetes medications, and records that do not match the HbA1c.