Causes of diabetes
Diabetes is a metabolic and endocrine disorder that results in an inability to metabolize sugar properly. Central to this internal process is a hormone called insulin, which helps the body turn sugar into fuel.
Diabetes can develop in several ways.
Insulin sensitivity and resistance in Type 2 diabetes
Insulin sensitivity is a phrase that describes a cell’s ability to respond appropriately to insulin—to take glucose out of the bloodstream and use it for energy or store it for future energy use.
Poor insulin sensitivity is sometimes called insulin resistance. When this occurs, a cell will not get the message about what to do with the glucose as quickly, and the body will have to produce more insulin for cells to respond appropriately.4
Insulin resistance is not necessarily the same thing as diabetes, but it is often considered a precursor to developing Type 2 diabetes. Like Type 2 diabetes itself, the condition can be brought on by genetic or lifestyle factors.4
Insulin sensitivity and anorexia
Diabetes and eating disorders share many connections, primarily through the way they both impact food intake, blood sugar, and several internal processes.
However, the question of how anorexia influences insulin sensitivity and the body’s reaction to glucose is a complicated one. While AN does not directly lead someone to develop diabetes, the disordered eating behaviors involved in the condition can have an impact on these other diabetes-adjacent factors.
Anorexia nervosa and insulin levels
Connections between AN and insulin resistance have been studied as far back as 1988.5 In that seminal analysis, fasting blood glucose levels—or blood sugar levels after a period of not eating—were compared to insulin levels in patients with AN, with the data suggesting a degree of insulin resistance. Still, these effects seemed to be at least partially reversed once patients began safely refeeding or achieved weight gain.5
A more recent study connected AN to possible insulin resistance through cortisol.6 One of the main stress hormones produced by the body, cortisol, can impact some internal functions, and this study found that patients with AN may produce more cortisol, which could lead to higher levels of insulin resistance.6
Yet another examination showed that insulin sensitivity could change throughout the recovery process, with those in the refeeding stage potentially at a higher risk of developing insulin resistance.7
Essentially, these mixed findings have led to a lack of clarity around long-term fasting, refeeding, and insulin sensitivity in people with AN. What is clear is that those struggling with anorexia nervosa should proceed with refeeding carefully, ideally under the guidance of doctors, to help avoid any potential health complications.
Does having anorexia predispose someone to developing diabetes?
While AN has sometimes been connected to insulin resistance, the condition ultimately isn’t considered a risk factor for developing Type 2 diabetes.1 Still, other factors may influence the onset of this condition.
If someone has a family history of diabetes or other risk factors for developing Type 2 diabetes, they may still develop the condition, prediabetes, or insulin resistance, regardless of whether they struggle with anorexia nervosa.
What is “diabulimia”?
Diabulimia is not an official medical term, but it describes a dangerous behavioral pattern around diabetes management when someone with Type 1 diabetes will withhold insulin therapy to lose weight.8
When a patient has Type 1 diabetes and is not receiving enough insulin to utilize glucose in the blood properly, their body's cells will turn elsewhere for energy sources, including fat and protein stores. However, the lack of glucose means these sources will not correctly “feed” the cells.8
Insulin helps cells access energy, and without it, cells will essentially starve, no matter how much food someone eats. When this occurs, metabolic and physiologic changes happen that can be extremely dangerous.
When cells do not receive enough energy, it can lead to extreme malnourishment, dehydration, and dangerously high blood sugar levels. And the physical complications that result from these issues—including kidney and liver disease, muscle atrophy, and a higher risk of developing infections—can be debilitating or even deadly.8
Finding help for anorexia nervosa or diabulimia
If you or a loved one are struggling with anorexia nervosa, developing disordered eating habits, or exhibiting symptoms of diabulimia, such as intentionally skipping insulin injections, it’s essential to seek out help.
Your physician, therapist, or mental health professional can be a good point of contact, helping you receive an official diagnosis or determine the next best steps for finding help.