The problem often starts by accident. A teen or young adult with Type 1 forgets an insulin dose or two and notices a few pounds drop off quickly. If she welcomes that weight loss, she may figure: Why not skip another dose?

If this becomes a habit, the person may have diabulimia, a diabetes-related eating disorder. It's dangerous, and it's more common than you might think. In one study, researchers found about one in three women with Type 1 diabetes reported restricting their insulin (skipping injections or manipulating the insulin pump so they receive less insulin).

Related: Teen Mental Health Problems: The Statistics Are Eye-Opening

Calories down the drain

“Diabulimia” is a take-off on “bulimia,” the eating disorder in which patients binge on vast quantities of food, then purge by vomiting or using laxatives. Luis Gonzalez-Mendoza, MD, director of pediatric endocrinology at Nicklaus Children's Hospital in Miami, has treated patients with diabulimia. "What happens is, they come to the realization that if they eat and don't give themselves insulin, those calories are going down the drain and won't reflect on their weight," he says.

In people with Type 1 diabetes, the body doesn’t produce enough insulin. Insulin injections are needed to help sugar enter cells so it can be used for energy. Without insulin, sugar (and calories) spill into the urine and don't show up on the scale.

People with Type 1 diabetes have often been counting carbs and calories for a long time, says Gonzalez-Mendoza. (Balancing insulin with carbs at each meal and snack is important to keeping blood sugar levels in the target range.) That close attention to food and food labels helps them control the disease, but it also may make them vulnerable to an eating disorder — they know how to “work the system,” so to speak.

Related: Orthorexia: When Healthy Eating Becomes an Obsession

Risks of diabulimia

Insulin restriction can be extremely dangerous and may lead to early death.

Ketones, chemicals produced when the body burns fat instead of glucose due to an insulin shortage, can accumulate to unsafe levels in the blood, leading to a condition known as diabetic ketoacidosis. Blood glucose rises to unsafe levels.

In the study that found nearly one in three women reported restriction, the researchers followed those women for 11 years. During that time, the risk of death was three times higher in women who restricted insulin, even after taking into account differences in their age, body mass index (BMI) and blood sugar control. Of the 234 women, 71 reported insulin restriction at the study start. By the end, 26 women had died, and those who did reported more restricted insulin at the beginning of the study.

Signs to watch for

If the ketone levels get too high, it can make the breath smell like rancid apples and cause abdominal pain, Gonzalez-Mendoza says. Nausea and vomiting are other potential signs of restricting insulin, he says.

Other possible signs, according to the National Eating Disorders Association:

  • Having persistent thirst or frequent urination
  • Being preoccupied with body image
  • Being depressed or moody or very tired
  • Losing weight without obvious effort
  • Canceling doctors' appointments
  • Being secretive about blood sugars, shots and or eating

Treating diabulimia

People with diabulimia may need psychological intervention, such as therapy sessions aimed at changing their behavior. "If you catch them early, you usually don't have to go that way," Gonzalez-Mendoza says. He finds some teens will restrict insulin temporarily, such as when they are preparing for a big event in their lives and want to lose some weight.

Gonzalez-Mendoza tries to explain the dangers to his patients. "I try to tell them that starvation and insulin deficiency are similar situations, and you are stacking one on top of the other [when you restrict insulin]." When he suspects someone is restricting insulin he gets other health care providers, such as diabetes educators and nurses, involved. He also may increase the frequency of visits to keep better tabs on the patient.

If he catches patients who have just begun to restrict insulin, Gonzalez-Mendoza finds he can usually get them back on track. However, intervention might be needed if it looks like it's becoming a habit, he says.

The National Eating Disorders Association offers referrals to specialists with experience in treating the disorder.

Related: 4 Ways to Find Affordable Mental Health Care

Kathleen Doheny is a Los Angeles journalist specializing in health, behavior and fitness topics.