What Should You Do if You Have Prediabetes?
Start a structured lifestyle change program immediately. The most effective action is losing 5 to 7 percent of your body weight through dietary improvements and increasing physical activity to at least 150 minutes per week. Ask your doctor about referral to a CDC-recognized Diabetes Prevention Program, which provides coaching and support to help you make lasting changes.
A prediabetes diagnosis is a critical window of opportunity. The landmark Diabetes Prevention Program trial, published in the New England Journal of Medicine in 2002, demonstrated that intensive lifestyle intervention reduced the progression from prediabetes to type 2 diabetes by 58 percent over three years. This benefit was even greater in participants aged 60 and older, who achieved a 71 percent reduction. The lifestyle intervention focused on two primary goals: achieving 7 percent weight loss (approximately 15 pounds for a 200-pound person) and completing 150 minutes per week of moderate-intensity physical activity such as brisk walking.
The CDC-recognized National Diabetes Prevention Program (National DPP) translates this research into community-based group programs available across the United States. These yearlong programs, covered by many insurance plans and Medicare, include 16 weekly core sessions followed by monthly maintenance sessions. Trained lifestyle coaches guide participants through goal-setting, healthy eating, physical activity planning, stress management, and problem-solving barriers to change. The CDC reports that National DPP participants lose an average of 5 percent of their body weight and reduce their risk of developing type 2 diabetes by 58 percent.
Beyond formal programs, immediate dietary and activity changes make a measurable difference. Replace sugar-sweetened beverages with water, choose whole grains over refined grains, increase vegetable intake to fill half your plate at each meal, take a 15-minute walk after meals to lower postprandial blood glucose, and aim for 7 to 8 hours of quality sleep per night. Research from Diabetes Care shows that even modest weight loss of 2 to 3 percent of body weight improves insulin sensitivity.
The DPP trial showed intensive lifestyle intervention reduced progression from prediabetes to type 2 diabetes by 58 percent
What Is Prediabetes and Who Is at Risk?
Prediabetes is a metabolic condition where blood sugar levels are elevated above normal but not high enough for a diabetes diagnosis. The CDC estimates that 98 million American adults — approximately 38 percent of the adult population — have prediabetes, and more than 80 percent of them are unaware of their condition.
Prediabetes reflects early insulin resistance and impaired beta cell function. In this stage, the pancreas still produces insulin, but the body's cells do not respond to it as effectively as they should. The pancreas compensates by producing more insulin, maintaining near-normal blood glucose levels, but this compensatory mechanism eventually becomes insufficient. Without intervention, the National Institute of Diabetes and Digestive and Kidney Diseases estimates that 15 to 30 percent of people with prediabetes will develop type 2 diabetes within 5 years.
Risk factors for prediabetes mirror those for type 2 diabetes and include being overweight or obese (especially with excess abdominal fat), being physically inactive, having a first-degree relative with type 2 diabetes, belonging to certain ethnic groups (African American, Hispanic, Native American, Asian American, or Pacific Islander), age 45 or older, history of gestational diabetes, having polycystic ovary syndrome, high blood pressure, low HDL cholesterol, high triglycerides, sleep apnea, and smoking. The ADA recommends screening all adults starting at age 35, and earlier for those with risk factors, using A1C, fasting glucose, or oral glucose tolerance testing.
The CDC estimates 98 million American adults have prediabetes and over 80 percent are unaware
- Overweight or obese, especially with central (abdominal) obesity
- Physical inactivity (less than 150 minutes of exercise per week)
- First-degree relative with type 2 diabetes
- African American, Hispanic, Native American, Asian American, or Pacific Islander ethnicity
- Age 45 or older
- History of gestational diabetes or delivering a baby weighing over 9 pounds
- Polycystic ovary syndrome (PCOS)
- High blood pressure (140/90 mmHg or higher) or on hypertension medication
- HDL cholesterol below 35 mg/dL or triglycerides above 250 mg/dL
How Is Prediabetes Diagnosed?
Prediabetes is diagnosed using three possible blood tests: A1C of 5.7 to 6.4 percent, fasting plasma glucose of 100 to 125 mg/dL, or a 2-hour oral glucose tolerance test result of 140 to 199 mg/dL. The ADA recommends that abnormal results be confirmed with a repeat test unless there is a clear clinical diagnosis.
Each diagnostic test has advantages and limitations. The A1C test is convenient because it does not require fasting and reflects average blood glucose over two to three months. However, A1C can be unreliable in people with hemoglobin variants (common in African American, Mediterranean, and Southeast Asian populations), iron deficiency anemia, recent blood loss or transfusion, or pregnancy. The fasting plasma glucose test requires an 8-hour overnight fast and is sensitive for detecting impaired fasting glucose. The oral glucose tolerance test, which measures blood sugar after a 75-gram glucose load, is the most sensitive test for detecting prediabetes but is time-consuming and less reproducible.
The ADA considers all three tests acceptable for screening and diagnosis. If one test is in the prediabetes range, repeating the same test or performing a different test to confirm the result is recommended. Importantly, people can have prediabetes by one criterion but not another, as impaired fasting glucose and impaired glucose tolerance reflect different aspects of glucose metabolism. Having both abnormalities confers higher risk of progressing to diabetes. The ADA recommends testing every three years if results are normal, and annually if results are in the prediabetes range.
How Effective Is Exercise in Preventing Diabetes?
Exercise is one of the most powerful tools for preventing type 2 diabetes. The DPP trial showed that 150 minutes per week of moderate-intensity exercise, combined with modest weight loss, reduced diabetes risk by 58 percent. Exercise improves insulin sensitivity, lowers blood glucose, reduces visceral fat, and provides cardiovascular benefits.
Physical activity improves insulin sensitivity through multiple mechanisms. During exercise, muscle contractions activate glucose transporters (GLUT4) that move glucose from the blood into muscle cells independently of insulin. This effect lasts for 24 to 72 hours after exercise, which is why the ADA recommends no more than two consecutive days without physical activity. A meta-analysis published in Diabetes Care found that structured exercise programs reduce A1C by an average of 0.66 percentage points in people with type 2 diabetes, comparable to some glucose-lowering medications.
Both aerobic exercise and resistance training are beneficial, and combining them appears optimal. Brisk walking is the most accessible and well-studied form of aerobic exercise for diabetes prevention. A large Finnish Diabetes Prevention Study demonstrated that participants who walked at least 2.5 hours per week had significantly lower diabetes incidence. Resistance training two to three times per week increases muscle mass, which is the primary site of insulin-stimulated glucose disposal. The ADA recommends 150 minutes per week of moderate-intensity aerobic activity or 75 minutes of vigorous activity, plus two or more sessions of resistance training.
The Finnish Diabetes Prevention Study showed that participants who walked at least 2.5 hours per week had significantly lower diabetes incidence
What Role Does Weight Loss Play in Diabetes Prevention?
Weight loss is the single most important factor in preventing progression from prediabetes to type 2 diabetes. Losing just 5 to 7 percent of body weight reduces diabetes risk by 58 percent. Even greater weight loss provides additional benefits, with the DiRECT trial showing that weight loss of 15 kg or more achieved diabetes remission in 86 percent of participants.
The relationship between weight loss and diabetes prevention is dose-dependent: more weight loss generally means greater risk reduction. In the DPP trial, participants who achieved the 7 percent weight loss goal had a 58 percent lower risk of developing diabetes, but those who lost 10 percent or more had even greater protection. The ADA recommends a caloric reduction of 500 to 750 calories per day, which typically produces a weight loss rate of 1 to 2 pounds per week. Sustainable weight loss through dietary modification combined with physical activity is more effective than diet alone.
For individuals with a BMI of 35 or higher who have not achieved adequate weight loss through lifestyle changes, the ADA notes that bariatric surgery can effectively prevent or achieve remission of type 2 diabetes. The Swedish Obese Subjects study demonstrated that bariatric surgery reduced the incidence of type 2 diabetes by 78 percent over 15 years compared to usual care. Anti-obesity medications such as semaglutide (Wegovy), tirzepatide (Zepbound), and liraglutide (Saxenda) are also increasingly used in people with prediabetes and obesity to achieve meaningful weight reduction.
The DPP showed that participants achieving 7 percent weight loss had a 58 percent lower risk of developing type 2 diabetes
Should You Take Medication to Prevent Diabetes?
Metformin is the only medication recommended by the ADA for diabetes prevention, and only for select high-risk individuals. The DPP trial showed metformin reduced diabetes risk by 31 percent, compared to 58 percent for lifestyle intervention. Metformin may be most appropriate for people under 60, those with BMI over 35, or women with prior gestational diabetes.
While lifestyle intervention is more effective overall, metformin offers a viable alternative or complement for certain populations. In the DPP trial, metformin was most effective in participants aged 25 to 44 (44 percent risk reduction), those with BMI of 35 or higher (53 percent risk reduction), and women with a history of gestational diabetes (50 percent risk reduction). The 15-year follow-up of the DPP (DPP Outcomes Study) confirmed that both lifestyle intervention and metformin continued to delay or prevent type 2 diabetes, with lifestyle intervention remaining superior overall.
The ADA Standards of Care 2025 state that metformin should be considered for diabetes prevention in people with prediabetes, especially those aged 25 to 59 with BMI of 35 or higher, women with prior gestational diabetes, or those with rising A1C despite lifestyle modifications. Metformin is inexpensive, generally well-tolerated, and may offer additional benefits including modest weight loss and potential cardiovascular protection. However, metformin should not replace lifestyle changes but rather complement them. Other diabetes medications have not been recommended for prevention due to insufficient evidence or unfavorable risk-benefit profiles.
The DPP trial showed metformin reduced diabetes risk by 31 percent overall, with greatest benefit in younger adults and those with severe obesity
How Does Prediabetes Affect Heart and Vascular Health?
Prediabetes is not just a warning sign for diabetes — it independently increases the risk of cardiovascular disease. People with prediabetes have a 15 to 30 percent higher risk of heart disease and stroke compared to those with normal blood sugar. Managing cardiovascular risk factors alongside blood sugar is essential.
The cardiovascular damage associated with elevated blood glucose begins in the prediabetes stage, well before a diabetes diagnosis. A meta-analysis published in the BMJ found that prediabetes, defined by impaired glucose tolerance, was associated with a 20 percent increased risk of cardiovascular events and a 13 percent increased risk of all-cause mortality. Even A1C levels in the prediabetes range of 5.7 to 6.4 percent have been associated with increased carotid intima-media thickness, a marker of early atherosclerosis, according to research in Diabetes Care.
Comprehensive cardiovascular risk management is therefore important for everyone with prediabetes. The ADA recommends blood pressure monitoring and treatment to maintain levels below 130/80 mmHg, lipid screening and statin therapy when indicated by cardiovascular risk assessment, smoking cessation, and aspirin therapy for those with established cardiovascular disease. Regular physical activity provides cardiovascular benefits beyond glucose lowering, including improved endothelial function, reduced inflammation, and favorable changes in lipid profiles. Addressing all modifiable cardiovascular risk factors is as important as preventing diabetes itself.
How Often Should Prediabetes Be Monitored?
The ADA recommends annual testing for people with prediabetes to detect any progression toward type 2 diabetes. Monitoring should include A1C or fasting glucose, blood pressure, lipid panel, and weight assessment. If you are enrolled in a diabetes prevention program, more frequent check-ins with your lifestyle coach are part of the program structure.
Annual testing allows early detection of progression to diabetes and timely treatment initiation. The ADA recommends using the same test type consistently for monitoring, as results can vary between A1C, fasting glucose, and oral glucose tolerance testing. If A1C is trending upward within the prediabetes range (approaching 6.4 percent), more frequent testing every 6 months may be warranted. Additionally, the ADA recommends that people with prediabetes be screened for comorbid conditions including hypertension, dyslipidemia, nonalcoholic fatty liver disease, and obstructive sleep apnea, all of which are more common in insulin-resistant states.
Long-term follow-up data from the DPP Outcomes Study show that the transition from prediabetes to diabetes can be delayed by years or even decades with sustained lifestyle changes. However, vigilance is important because beta cell function continues to decline over time in many people with prediabetes. The NIDDK recommends that people with prediabetes work closely with their healthcare team to set and track progress toward weight loss, physical activity, and dietary goals. Using health tracking apps, participating in diabetes prevention programs, and scheduling regular medical follow-up all contribute to successful long-term management.
The DPP Outcomes Study demonstrated that lifestyle intervention continued to delay diabetes development for at least 15 years
