It’s alarming but true that lean fit people who exercise can develop insulin resistance.

You’ve most likely heard of insulin resistance, and it seems that every article about insulin resistance contains the words overweight, obese, lack of exercise, inactive and poor diet (or something similar).

Read enough articles on insulin resistance and you’ll soon be convinced that only overweight (especially obese) people who never exercise get this prediabetic condition.

If you’re a lean, physically fit athlete, and especially if your diet restricts processed foods, trans fats, sat fats, white sugar and high fructose corn syrup, it will be very easy to believe that you can never, ever develop insulin resistance.

The body relies upon glucose for energy—not just the energy needed to play sports or pump iron, but the energy required on the cellular level: cellular metabolism.

When you eat carbohydrates (in the form of sugar or starch), they enter the bloodstream and raise blood sugar levels. In response, the pancreas secretes the hormone insulin.

There are insulin receptor sites on the surface of cells (e.g., muscle and liver cells).

The insulin binds to these receptors, causing uptake of the glucose by the cells from the bloodstream.

The glucose will be used as energy for cellular metabolism, or stored as glycogen in the liver for later use.

But what if these insulin receptors aren’t up to this task?

This is insulin resistance, according to Dr. David Edelson, MD, board certified in internal and bariatric medicine, one of the top obesity experts in the U.S., and founder and medical director for HealthBridge.

The receptors “seem to ignore the insulin, or require higher levels before they will respond,” he says. And what if there’s a short supply of these receptor sites? That, too, is insulin resistance.

Because the cells are not taking up the glucose the way they should, the pancreas may end up pumping out even more insulin, thus stressing this gland. In the early phases of insulin resistance, says Dr. Edelson, this will result in too much insulin in the blood (hyperinsulinemia).

Over time, this can cause “fatigue, fat gain around the midsection and eventually full-blown metabolic syndrome, but in the beginning there may be no noticeable symptoms,” says Dr. Edelson.“After a while, the pancreas can’t keep up.”

The result is that blood sugar levels remain elevated.  Left untreated, there is a 30 percent chance that insulin resistance will morph into type 2 diabetes. IR also raises the risk of heart disease, stroke and kidney damage.

If you’re a mean, lean and buff iron-pumping machine, and have a plant-based, mostly whole-foods organic diet, “You can still develop insulin resistance at some time in your life,” says Dr. Edelson.

However, it’s crucial to remember that remaining lean and fit through a healthful diet and rigorous exercise will substantially lower the odds of developing insulin resistance.

To learn what a lean, fit athlete or gym enthusiast with a clean diet can do to absolutely minimize the chance of getting insulin resistance, go to Part II of this article for Dr. Edelson’s recommendations.

Dr. Edelson is widely recognized as one of the nation’s top weight loss experts, and was listed in NY Magazine’s “Best Doctors of 2014” issue.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Shutterstock/vladee