Could you be one of the millions of American women who have prediabetes—but have no idea?

Last spring, I finally made it into my nurse practitioner’s office for a physical, my first one in about five years. (I’d been pregnant twice, moved across the country, bought and sold my first house—I’d been busy!) What I learned from my blood test results shocked and scared me: I was prediabetic.

Prediabetes isn’t a disease the way pneumonia or cancer is; it’s more like a big, flashing red warning that you’re headed in the wrong direction. "It’s a sign you may develop type 2 diabetes in the future," says John Buse, MD, director of the UNC Diabetes Care Center in Chapel Hill, North Carolina.

As a longtime health journalist, I know having full-blown type 2 diabetes is no joke: That condition can double a person’s risk of dying of heart disease, the number one killer of American women. It’s also linked to many cancers and, if left untreated, to nerve and kidney damage and vision problems. But prediabetes can be harmful, too. "Even at the prediabetic stage, there’s an increased risk for heart disease and stroke," says Don Kain, RD, a certified diabetes educator at Oregon Health and Science University in Portland. (In fact, prediabetes alone increases your risk of heart disease by 10 percent.)

Prediabetes is easy to diagnose via a simple blood test called the A1C, which measures how much of your hemoglobin—a redblood-cell protein—has sugar attached to it. (Below 5.7 percent is normal, and anything between that and 6.4 is considered prediabetic; 6.5 and above earns you a diabetes diagnosis.) Yet even though nearly a third—29 percent— of American women are prediabetic, almost 90 percent of them don’t know it, according to the Centers for Disease Control and Prevention.

One of the biggest concerns with having too much sugar circulating in your blood is that it may trigger chronic inflammation that in turn is associated with everything from heart attack and cancer to Alzheimer’s. “The purpose of the sugar in your blood is to be moved into your body cells as fuel—it’s really not supposed to be just hanging around in there,” says Lindsay Malone, RD, a dietitian at the Cleveland Clinic. It also triggers your body to pump out extra insulin in an effort to process the blood sugar. Excess insulin causes even more inflammation, and the whole process taxes the pancreas over time.

What’s your risk?

Once I researched the risk factors for prediabetes, the fact that I had it wasn’t all that surprising. Having a baby who weighed more than nine pounds at birth—check. Family members with diabetes—check. BMI over 25—check and mate.

Although I couldn’t change my genetics or the size of my adorably chubby baby, I knew that my habits played a role. I’d lost my grip on my formerly healthy intuitive-eating style and regular exercise routine since my daughter was born in 2014. What’s more, the stress of being self-employed and having two kids had triggered some old emotional overeating habits, and I’d put on a lot of weight.

But here’s the thing: While not exercising and a poor diet increase your risk of prediabetes, someone who seems pretty healthy—has a BMI in the "normal" range, doesn’t smoke or eat junk food all the time—can get it, too, says Samar Hafida, MD, an endocrinologist at Harvard Medical School’s Joslin Diabetes Center. "Ethnicity, for example, is an independent risk factor for diabetes. Native Americans, Latinos, African Americans, and Asian Americans are all at a higher risk of developing prediabetes than others," says Dr. Hafida. Other things that boost your risk: polycystic ovary syndrome, high blood pressure, and a large waist size.

Beating the trend

My provider assured me that I could turn things around. “The most effective way to prevent or ‘reverse’ prediabetes is with better dietary choices and exercise,” says Dr. Hafida. “Even modest aerobic exercise, like brisk walking, improves insulin sensitivity and reduces fat stores deposited in the belly area, both of which help prevent diabetes." The Mediterranean diet can reduce the risk of diabetes, and some specific foods, such as nuts, berries, whole grains, and yogurt, seem to have protective benefits, she says.

Of course, diet and exercise are great for you even if you don’t lose weight. But the experts I spoke with insist that weight does matter for diabetes and prediabetes risk: If you’re significantly overweight, studies show that losing as little as 5 percent to 7 percent of your body weight can have an impact, says Kain.

Because I have a history of binge-eating disorder and overexercising, anything that smacks of "dieting" won’t work for me. So I took it slow: First, I joined a gym and worked up to doing cardio intervals on a treadmill or stationary bike three times a week. I also bought a cute step tracker and aimed to get at least 5,000, then 6,000, nongym steps a day. (Next goal: 8,000!) Recent research has found that people who built up to 10,000 daily steps over five years improved their insulin sensitivity.

I also made gentle changes to my diet, replacing roughly half the grains and bready carbs in my usual meals with green veggies. I still ate my favorite foods, but differently— like ordering burgers wrapped in lettuce or turning taco night at home into taco-salad night. And to address the emotional overeating, I saw a therapist and started doing mindfulness meditation. I don’t track my weight (scales and eating-disorder histories often don’t mix), but my pants felt comfier, and I had to start using the tightest hooks on my bras.

After about six months, I headed back to the doctor. Happily, my efforts paid off: My latest A1C test shows that I’m no longer prediabetic. But with my risk factors, I know I need to keep going. And I want to: I feel accomplished, energetic, and happier. These changes have made not just my blood sugar better but my life.