Prediabetes develops when your body starts losing its ability to manage blood sugar effectively, but hasn’t crossed the threshold into type 2 diabetes. About 115 million U.S. adults currently have it, and most don’t know. What pushes someone into that territory is a combination of how their body handles insulin, how much body fat they carry (and where), their genetics, and daily habits like movement and sleep.
How Blood Sugar Regulation Breaks Down
To understand what makes someone prediabetic, it helps to know what’s happening inside the body. Normally, when you eat, your pancreas releases insulin, a hormone that tells your cells to absorb sugar from the bloodstream for energy. In prediabetes, two things start going wrong at once.
First, your cells become less responsive to insulin. This is called insulin resistance. Your muscles, liver, and fat cells don’t absorb sugar as efficiently, so glucose builds up in the blood. Second, the insulin-producing cells in your pancreas (called beta cells) start to wear out. They’ve been working overtime to compensate for the resistance, and eventually they can’t keep up. Research suggests that beta cell dysfunction is actually the more critical factor in whether someone develops type 2 diabetes, even more so than insulin resistance alone.
Excess body fat, particularly fat stored around the organs and in the pancreas itself, accelerates both problems. Fat tissue releases inflammatory signals and hormones that interfere with insulin’s ability to do its job. The more fat in and around the pancreas and liver, the harder it becomes for those organs to regulate blood sugar. Over time, the beta cells sustain damage from oxidative stress and inflammation, and some of them die off entirely.
The Numbers That Define Prediabetes
Prediabetes is defined by specific blood test results. The most common test is the A1C, which measures your average blood sugar over the past two to three months. A normal A1C is below 5.7%. Prediabetes falls between 5.7% and 6.4%. At 6.5% or above, it’s diabetes.
Doctors may also use a fasting blood glucose test or an oral glucose tolerance test to confirm the diagnosis. Without any intervention, roughly 5 to 10% of people with prediabetes progress to full type 2 diabetes each year.
Body Weight and Where You Carry It
Carrying excess weight is the single biggest modifiable risk factor. Adults with a BMI of 25 or higher are considered overweight and face elevated risk. That threshold is lower for Asian Americans, where a BMI of 23 or higher already signals increased risk, reflecting differences in how body fat is distributed across populations.
Where your body stores fat matters as much as how much you carry. Waist circumference is a practical proxy for the visceral fat that surrounds your organs and drives insulin resistance. Men with a waist measurement over 40 inches and women with a waist over 35 inches are at notably higher risk. You can be at a normal weight by BMI standards and still carry enough abdominal fat to push your blood sugar into the prediabetic range.
Family History and Genetics
Having a parent or sibling with type 2 diabetes increases your odds of developing the condition by two to six times compared to someone without that family history. One long-term study found that by age 80, 38% of people with a first-degree relative who had type 2 diabetes developed it themselves, compared to just 11% of those with no family history.
Genetics influence both sides of the equation. Some inherited variants affect how well your beta cells produce and release insulin, while others shape how sensitive your tissues are to it. Genetic studies have identified more variants linked to beta cell function than to insulin resistance, reinforcing that your pancreas’s ability to keep up with demand is a key inherited vulnerability. That said, genes load the gun but lifestyle pulls the trigger. A strong family history doesn’t guarantee prediabetes, and having no family history doesn’t make you immune.
Ethnicity and Demographic Patterns
Prediabetes rates vary meaningfully across racial and ethnic groups. After adjusting for factors like age, weight, and income, Asian adults have a 26% higher risk of prediabetes than white adults, Black adults have a 17% higher risk, and Hispanic adults have a 10% higher risk. These differences reflect a mix of genetic susceptibility, body composition patterns, and socioeconomic factors that influence diet, activity, and access to care.
Asian populations, for instance, tend to develop insulin resistance at lower body weights, which is why screening thresholds start at a lower BMI. Age is another major factor: more than half of adults 65 and older, about 31 million people in the U.S., have prediabetes.
Sedentary Time and Physical Activity
Sitting for long stretches directly contributes to insulin resistance, independent of whether you also exercise. A study tracking healthy middle-aged adults over about five and a half years found that the more time participants spent sedentary, the higher their fasting insulin levels climbed, even after accounting for age, body fat, and how much moderate or vigorous exercise they did. In other words, a morning jog doesn’t fully cancel out eight hours of sitting.
The flip side is encouraging. Regular physical activity improves insulin sensitivity through multiple pathways: muscles that contract regularly pull sugar from the bloodstream more efficiently, and exercise reduces visceral fat over time. The landmark Diabetes Prevention Program found that 150 minutes per week of moderate physical activity, combined with a 5 to 7% loss of body weight, reduced the risk of progressing from prediabetes to diabetes by 58%. For a 200-pound person, that’s a loss of just 10 to 14 pounds.
Sleep and Hormonal Conditions
Poor sleep and certain hormonal conditions create a less obvious path to prediabetes. Obstructive sleep apnea, where breathing repeatedly stops and restarts during sleep, triggers a chain reaction that worsens blood sugar control. The repeated drops in oxygen and fragmented sleep activate your body’s stress response, increase inflammation, impair the way cells use energy, and directly promote insulin resistance and beta cell damage. Many people with sleep apnea don’t realize they have it, so the metabolic damage accumulates quietly.
Polycystic ovary syndrome (PCOS) is another underrecognized driver. Insulin resistance is a core feature of PCOS, not just a side effect. The hormonal imbalances characteristic of the condition, particularly elevated androgens, can also increase susceptibility to sleep apnea, creating a compounding loop. Women with PCOS should be screened for prediabetes regularly, even if their weight is normal.
What Reversal Actually Looks Like
Prediabetes is not a one-way street. The same Diabetes Prevention Program that established the 5 to 7% weight loss target showed that lifestyle changes were more effective than medication at preventing progression to diabetes. The core formula is straightforward: move more, reduce calorie intake enough to lose a modest amount of weight, and prioritize foods that don’t spike blood sugar sharply (vegetables, whole grains, lean protein, healthy fats).
The changes don’t need to be dramatic to be effective. Walking briskly for 30 minutes five days a week meets the 150-minute threshold. Losing even 5% of your body weight measurably improves insulin sensitivity and gives your beta cells breathing room. The earlier you catch prediabetes and act on it, the better your chances of returning to normal blood sugar levels, because beta cells that are overworked but still alive can recover function once the demand on them eases.