Does insulin resistance lead to binge eating or is it the other way around? Nutrition Diva looks into what researchers have found about Binge Eating Disorder and insulin resistance.
Amy asks: "Has anyone considered the correlation between undiagnosed insulin resistance and binge eating or emotional overeating?"
Researchers have, in fact, detected an association between decreased insulin sensitivity (or insulin resistance) and binge eating disorder. These two conditions frequently occur together. But we’re still not sure exactly how they are linked.
What is insulin resistance?
Insulin is a hormone that’s secreted by the pancreas when your blood sugar rises—typically after you eat. Its job is to clear glucose out of the blood and into the cells, where it can be either used or stored for future use. When our cells become less sensitive to the effects of insulin, the glucose just keeps circulating in the blood, leading to high blood sugar. Decreased insulin sensitivity is often a precursor to Type 2 diabetes.
Risk factors for insulin resistance include genetic predisposition, sedentary lifestyle, and excess body weight, especially when you carry your weight around the middle. However, it is possible to develop insulin resistance even if you are normal weight. It’s also possible to have excess weight without being insulin resistant.
What is binge eating?
Many of us occasionally engage in behavior that we might describe as binging—whether that’s on Netflix or ice cream. But Binge Eating Disorder (BED) is a medical condition characterized by repeated episodes of eating unusually large quantities of food and feeling a loss of control.
It’s important to note that it’s possible to have BED without being overweight, and vice versa. However, people who suffer from BED are more likely to be overweight. And people who are overweight are more likely to have insulin resistance. The question that some researchers are now asking is whether binge eating might be a separate risk factor for developing decreased insulin sensitivity. Alternatively, could insulin resistance possibly lead to binge eating, or is the association simply coincidental?
Does binge eating lead to insulin resistance?
Eating an extremely large amount of food in a single sitting can cause short-term effects on insulin metabolism. And if that pattern were repeated, it could contribute to decreased insulin sensitivity over time. So, it’s plausible that binge eating behaviors could provoke insulin resistance—independent of any weight gain that might occur.
But it's also possible that the "causal arrow" might actually be pointing in the other direction.
Does decreased insulin sensitivity lead to binge eating?
One potential consequence of insulin resistance is disordered appetite signaling. If your cells aren’t getting the glucose that’s released into your bloodstream after you eat, the brain might continue to receive the signal to eat—despite the fact that the body has plenty of fuel in the form of stored fat.
If this is true, then addressing the underlying insulin resistance (by lifestyle or, when necessary, medication) could help lessen the drive to eat, which might lead to reduced binging behavior.
The science to support this hypothesis is mixed. One study found no association between binge eating or emotional eating and insulin resistance in a group of men and women that included both overweight and normal-weight individuals.
Another study focused on patients who were suffering from both BED and obesity. They found that those with insulin resistance tended to have less severe BED and to have developed BED later in life. The study authors hypothesize that developing BED later in life might increase the likelihood of developing insulin resistance because people are just more likely to develop insulin resistance as they get older.
But you could look at those same data, squint your eyes a bit, and imagine a scenario in which insulin resistance leads to a mild form of BED, through its dysregulation of appetite signals.
Why does this matter?
Unfortunately, I don’t think we yet have enough information to reach a conclusion one way or another. (And the truth is probably not cut-and-dried.) But, aside from scientific curiosity, what difference might this make in how we approach the treatment and prevention of either Binge Eating Disorder or insulin resistance?
Amy specifically asked whether undiagnosed insulin resistance could be a factor in binge eating. But of the two, binge eating disorder is a lot more likely to go undiagnosed.
Eating disorders often fly below the radar and are not detected by healthcare professionals unless they are actively looking for them. And if it turns out that insulin resistance increases the likelihood of BED, this could potentially be a big problem.
Insulin resistance is often flagged by a routine blood test, and people are often counseled to lose weight as a way to improve their insulin sensitivity. But dieting behaviors can easily trigger or exacerbate BED. So it might be a good idea to screen people who are being treated for insulin resistance for eating disorders. This can be done with a short set of standardized interview questions.
It doesn’t really matter whether the binge eating is the cart or the horse in this situation. If BED is part of the picture, treating the eating disorder takes priority over losing weight. Attempting to lose weight without treating the underlying eating disorder can make both problems a lot worse. Even when an eating disorder is in remission, weight loss should be approached carefully and ideally in coordination with the mental health team.
Although insulin resistance could potentially play a role in the development of BED, this condition is not driven solely by physical hunger or even hormonal misfires. Generally, there are (treatable) psychological factors at work. If you wonder whether you might be suffering from BED (or any eating disorder), I want you to know that treatment is available and recovery is possible.
You can use the confidential screening tool available at the National Eating Disorders Association (NEDA) website to assess whether it might be time to seek professional support. And if you do need more support, NEDA has more resources, including a helpline and a referral network.