You don’t have to be overweight or obese to get type 2 diabetes. In fact, you can have high blood sugar even if you look thin. Around 10% to 15% of people with type 2 diabetes are at a healthy weight. It’s called lean diabetes. It may be a kind of “hybrid” of type 1 and type 2, says Mercedes Carnethon, a professor of preventive medicine at Northwestern University.
That means you may not make enough insulin or respond to it very well.
And you may have more fat than you think. “Normal weight individuals who go on to develop diabetes may have muscle that is heavily marbled in fat,” says Carnethon.
Experts don’t know the exact cause of lean diabetes. But you can get a blood sugar test to see if you have it. If you do, your doctor can help you find a treatment.
Who Gets Lean Diabetes?
Your genes and lifestyle play a role. In general, you’re 40% more likely to get diabetes if one of your parents has it. Lean diabetes may also happen if you don’t get enough nutrients before you’re born or when you’re a child, says Leon Fogelfeld, MD, chief of endocrinology at Cook County Hospital. And your chances of normal weight diabetes go up if you’re black or Asian, adds Carnethon.
Some other things also raise your odds. Those include if you:
- Smoke cigarettes
- Drink a lot of alcohol
- Are male
- Don’t exercise much
- Get short or bad sleep
- Have a poor diet
“We think those relative risk factors may end up tipping the balance for people who are at a high genetic risk based on family history,” says Carnethon.
Lean Diabetes and Blood Sugar Control
If you’re obese with type 2 diabetes, a medicine you take by mouth called metformin may help. When you take it, your pancreas can make more insulin. But that may not be enough if you have lean diabetes. Compared to an obese person with type 2, people with lean diabetes need insulin shots at a younger age, says Fogelfeld. That’s because certain cells in your pancreas called beta cells fail early and quick. This may happen because of your genes. But lifestyle factors like smoking and drinking make it worse.
What Is Skinny Fat?
Your body mass index (BMI) is a measure of your height and weight. Doctors often use this number to find out if you’re obese. But it doesn’t tell you anything about your body makeup. You may be less healthy if you have a lot of weight in your middle. “When fat is in the waist area, it tends to secrete more hormones that are bad for your blood vessels,” says Carnethon.
“Central obesity” can lead to high blood sugar because “the fat in the belly is able to produce substances that interfere with the action of insulin,” says Fogelfeld.
Will Exercise Help?
Your doctor probably won’t want you to lose weight. That’s because you may not have enough muscle mass. You could lose even more if you focus on aerobic workouts. That would be bad for your blood sugar and your bones.
Compared to fat, muscle does a better job of getting sugar out of your blood, says Carnethon. This helps you use it for energy. She and her colleagues think strength training instead of cardio may help you better manage your lean diabetes. They’re doing more research to find out.
“If we can help build muscle, then there’s more receptors for the blood sugar to go to,” says Carnethon. “So maybe we can clear blood sugar from the bloodstream more efficiently.”
Symptoms May Be Hard to See
“Patients may have no clue,” says Berhane Seyoum, MD, chief of endocrinology at DMC Harper University Hospital. That’s why his team is trying to find an early way to screen for signs of an unhealthy metabolism and diabetes.
But you could start to pee more than normal or get thirsty. If you’re at a healthy weight, your doctor may not think your symptoms are from diabetes. That’s why “it’s always good to get a physical once a year to see what your blood sugar looks like,” says Seyoum.
How Do You Diagnose and Treat It?
Your doctor will want to rule out latent autoimmune diabetes in adults (LADA), says Alyson Myers, MD, an endocrinologist and medical director of inpatient diabetes at North Shore University Hospital. That’s a form of type 1 diabetes. A blood test will tell you if you have it.
Your treatment will be the same as other types of diabetes. Your doctor will give you metformin or insulin shots to help lower your blood sugar.
Ways to Stay Healthy
You can make some good lifestyle changes to lower your chances of getting lean diabetes. You should stop smoking and stay away from heavy alcohol use. Try to eat well. “A healthy diet is one that’s characterized by moderation and by regular intake of lean proteins, vegetables, fruit, and high-fiber carbohydrates,” says Carnethon.
You should also cut down on:
- Sugary snacks
- High-fat dairy
- Ultra-processed foods
- Deep-fried meals with a lot of fat
Why You Need Treatment
“It would be a mistake not to adhere to therapy just because you don’t have obesity,” says Carnethon. That’s because high blood sugar levels can hurt the small and large vessels that go to your eyes, kidneys, heart, and brain, she says. That means uncontrolled type 2 diabetes raises your chances of:
Research shows that diabetes may affect your health more if you at a healthy weight. This is called the “obesity paradox.” Doctors aren’t sure why this is the case. It’s possible you have another health condition.
Researchers will continue to look into how your genes, lifestyle, and pre-birth factors may affect your chances of lean diabetes. This may lead to new treatments. And it may help doctors learn how to prevent it in the future. For now, it’s a good idea to check in with your doctor about your blood sugar. Make sure to tell them if you have a family history of diabetes.