Prediabetes: How to Prevent It

The scourge of Type 2 diabetes in America is well documented. The Centers for Disease Control and Prevention count more than 34 million Americans who have been diagnosed with the disease, according to a 2020 report. But a lesser-known condition that should serve to warn people to take action — but too often isn’t — is far less acknowledged: prediabetes.

According to the CDC, more than 88 million American adults have prediabetes — and more disturbing, perhaps, is that 90% of them don’t even know they have it. That’s right: 1 in 3 U.S. adults is on a path to developing and living with diabetes, and they don’t realize it.

“We are also starting to see prediabetes in our children. Nearly 1 in 5 adolescents have prediabetes,” says Dr. Jay H. Shubrook, a professor of primary care and director of clinical research and diabetes services at Touro University California College of Osteopathic Medicine.

Here’s what you should know about prediabetes.

What Is Prediabetes?

Prediabetes “is a precursor to Type 2 diabetes. It means having higher blood sugars than what is considered normal, but not high enough to be labeled as having diabetes,” says Dr. Lyudmila Shvets-Gabriel, an endocrinologist with White Plains Hospital Physician Associates in Armonk, New York.

It takes a long time to go from “normal” blood sugar levels to diabetes, Shubrook says. “So we have the ability to identify a person who looks like they are on their way to diabetes. The good news is if we identify people who have prediabetes, there is a lot that can be done to help that person to prevent them from getting to diabetes.”

[READ: How Do I Know If I Have Diabetes?]

How Is Prediabetes Diagnosed?

There are a couple of ways to measure blood sugar levels, according to the American Diabetes Association.

A blood test known as the A1C test measures your average blood glucose levels, or blood sugar, for the past two to three months. The A1C ranges, from normal to diabetes, are:

Normal: less than 5.7%.

Prediabetes: 5.7% to 6.4%.

Diabetes: 6.5% and higher.

A fasting plasma glucose, or FPG, test checks blood sugar levels after fasting for at least eight hours before the test. The ranges here are:

Normal: less than 100 milligrams/deciliter.

Prediabetes: 100 to 125 mg/dL.

Diabetes: 126 mg/dL and higher.

The oral glucose tolerance test, or OGTT, checks your blood sugar levels before and two hours after you drink a diagnostic sweet drink. It reveals how your body processes sugar. Ranges are:

Normal: less than 140 mg/dL.

Prediabetes: 140 mg/dL to 199 mg/dL.

Diabetes: 200 mg/dL and higher.

Risk Factors

Type 2 diabetes and prediabetes share a common set of causes and risk factors. The CDC lists them as:

— Being overweight.

— Being 45 years or older.

— Having a parent, brother or sister with Type 2 diabetes.

— Being physically active less than three times a week.

— Ever having gestational diabetes (diabetes during pregnancy) or giving birth to a baby who weighed more than 9 pounds.

— Having polycystic ovary syndrome, or PCOS.

— Being African American, Hispanic/Latino American, American Indian, Pacific Islander or Asian American.

The American Diabetes Association has a diabetes risk test that you can complete to find out if you are at risk.

[See: The Best Diets to Prevent and Manage Diabetes.]


There are usually no symptoms with prediabetes. But it’s changing your blood chemistry in ways that will cause problems in the future.

Specifically, it targets insulin, a hormone made by the pancreas that helps cells process blood sugar into energy. Having any of the risk factors interferes with how the cells respond to insulin. As a result, the pancreas makes more insulin to compensate, but over time the pancreas fails to create enough insulin to maintain normal blood sugar levels. As they rise, they enter the range for prediabetes and, if unchecked, Type 2 diabetes.

And that begins the march to serious complications from the disease. “Long-term damage to organs such as heart, blood vessels, kidneys and nerves starts as early as in the prediabetes stage,” Shvets-Gabriel says.

“If nothing is done, the normal progression from prediabetes to Type 2 diabetes is about 11% per year,” Shubrook says. “The good news is there are a number of ways to reduce this risk.”

Best Ways to Prevent Prediabetes

“Maintaining a healthy weight is the best way from preventing prediabetes,” Shubrook says. Losing just a small amount of weight — around 5% to 7% of your total body weight, or 10 to 14 pounds if you weigh 200 pounds — can have a significant impact, the CDC says.

To do that, cut down on your sugary foods and beverages, and try to get at least 150 minutes a week of brisk walking or a similar activity. That’s just 30 minutes a day, five days a week.

To help, the CDC has created a lifestyle change program through its National Diabetes Prevention Program. It claims that the program can help lower the risk of developing Type 2 diabetes by as much as 58% (71% if you’re over age 60). The program includes:

— Working with a trainer to make realistic, lasting lifestyle changes.

— Learning how to eat healthy and add physical activity into your day.

— Finding out how to manage stress, stay motivated and solve problems that can slow your progress.

— Support from others with similar goals and challenges.

You can find a National Diabetes Prevention Program in your area by asking your doctor or visiting the CDC’s website.

For some patients with prediabetes, medications may help, including metformin, pioglitazone, acarbose and liraglutide, which have been shown to help reduce the progression from prediabetes to Type 2 diabetes. And along with lifestyle modifications and medication, “We also see patients who are able to reverse prediabetes by managing secondary factors like obesity with surgical intervention,” Shvets-Gabriel says, such as bariatric weight-loss surgery. “Individual therapy options should be tailored towards each patient.”

A registered dietitian nutritionist who specializes in diabetes care and education can also offer customized guidance and support about dietary changes that can help keep you from progressing toward diabetes. Look for RDN and DCES credentials when seeking nutritional advice related to diabetes.

[READ: How Long Does It Really Take to Make Healthy Eating and Exercise a Habit?]

What Else Should You Know?

Shvets-Gabriel says that early intervention is critical to catch prediabetes before it progresses to diabetes. “I always encourage patients to be their own advocates and be involved in their own medical care,” she says. “Do your research and ask questions so you are more aware of what you can do to modify your risk factors day to day. Primary care physicians are usually the gatekeepers, so patients should ask and remind their doctor to screen them for diabetes or prediabetes at their annual visits.”

Shubrook agrees: “There is a lot you can do to prevent getting diabetes. Knowledge is power, and you can take control.”

More from U.S. News

What Are the Causes of Diabetes?

Questions to Ask an Endocrinologist

Top 10 Healthy Foods to Have in Your Kitchen

Prediabetes: How to Prevent It originally appeared on

Update 10/19/21: This story was previously published at an earlier date and has been updated with new information.

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