Researchers followed over 700 adults in Italy for four years to see what happens to people with prediabetes—a condition where blood sugar is higher than normal but not yet diabetic. The good news? Nearly 44% of people with prediabetes returned to normal blood sugar levels, while only about 13% developed type 2 diabetes. The study found that people who became more active, ate Mediterranean-style foods, and lost weight were most likely to reverse their prediabetes. This research shows that lifestyle changes—not just medication—can be powerful tools for preventing diabetes before it starts.

The Quick Take

  • What they studied: Whether people with prediabetes (higher-than-normal blood sugar) would develop type 2 diabetes or return to normal blood sugar levels over four years, and what lifestyle factors made the difference.
  • Who participated: 742 adults living in Palermo, Italy, who were tracked from 2011 to 2015. About 31% had prediabetes when the study started.
  • Key finding: Of people with prediabetes, 44% returned to normal blood sugar, 13% developed diabetes, and 43% stayed the same. Those who exercised more, followed a Mediterranean diet, and lost weight were most likely to improve.
  • What it means for you: If you have prediabetes, lifestyle changes like eating healthier Mediterranean foods and being more physically active may help you avoid developing diabetes. However, individual results vary, and you should work with your doctor on a plan tailored to you.

The Research Details

This was a follow-up study where researchers tracked the same group of people over four years. In 2011, they measured blood sugar levels, asked about exercise and eating habits, and told participants about their health status with suggestions for improvement. In 2015, they measured the same things again to see who had improved, stayed the same, or gotten worse.

The researchers looked at three main blood sugar measurements: fasting glucose (blood sugar after not eating overnight), HbA1c (a test showing average blood sugar over three months), and glucose after eating. They also tracked body weight, waist size, how much people exercised, and what they ate, including a special score for Mediterranean diet quality.

Following the same people over time is valuable because it shows real-world changes in actual people’s lives, not just laboratory results. By measuring multiple factors—blood sugar, exercise, diet, and body measurements—the researchers could see which lifestyle changes were most connected to improvement or decline.

This study is reasonably reliable because it tracked a large, representative group of real people in their actual community rather than in a controlled lab setting. However, about 40% of the original participants didn’t complete the follow-up, which could affect results. The study didn’t randomly assign people to different treatments, so we can see associations but not prove that one thing directly caused another.

What the Results Show

Among the 742 people with complete information, about 31% had prediabetes in 2011. Four years later, the group split into three paths: 44% of those with prediabetes returned to normal blood sugar levels, 13% developed type 2 diabetes, and the rest stayed in the prediabetic range.

People who improved (returned to normal blood sugar) had several things in common: they ate fewer calories daily, their diet had a lower glycemic index (meaning foods that don’t spike blood sugar as much), and they followed Mediterranean diet patterns more closely. They also tended to be more physically active.

In contrast, people whose prediabetes turned into diabetes ate more calories, were more sedentary, and didn’t follow Mediterranean eating patterns as well. Age and sex also mattered—older adults and men were more likely to progress to diabetes.

Interestingly, 106 people who had normal blood sugar in 2011 developed prediabetes by 2015, suggesting that prevention is important even for those without prediabetes.

Body measurements told an important story: people with prediabetes had higher body weight, BMI, and waist circumference than those with normal blood sugar. Those whose prediabetes became diabetes had even higher measurements. This suggests that central obesity (extra weight around the belly) is particularly connected to diabetes development. The study also found that the Mediterranean diet score improved most in people who reversed their prediabetes, indicating that this specific eating pattern may be especially helpful.

This research aligns with previous studies showing that lifestyle changes can prevent or delay type 2 diabetes. The finding that 44% of people reversed prediabetes is encouraging and consistent with other research suggesting prediabetes isn’t always a one-way path to diabetes. The emphasis on Mediterranean diet patterns fits with existing evidence that this eating style benefits blood sugar control and heart health.

The study lost track of about 40% of original participants, which could bias results if those people had different outcomes. The researchers couldn’t prove that specific lifestyle changes directly caused improvements—only that they were associated with better outcomes. The study was conducted in one Italian city, so results may not apply equally to all populations. Additionally, people knew they had prediabetes and received lifestyle advice, which may have motivated some to change their habits, making it hard to separate the effect of knowing versus the effect of actual lifestyle change.

The Bottom Line

If you have prediabetes: (1) Increase physical activity—aim for regular exercise most days of the week (moderate confidence); (2) Follow a Mediterranean-style diet emphasizing vegetables, whole grains, olive oil, and fish while reducing processed foods (moderate-to-strong confidence); (3) Reduce daily calorie intake if overweight, particularly reducing belly fat (moderate confidence); (4) Work with your doctor to monitor blood sugar regularly. These changes may help reverse prediabetes or prevent progression to diabetes.

This research is most relevant for people with prediabetes, people with family history of diabetes, and anyone over 45 or with excess weight. It’s also important for healthcare providers counseling patients about diabetes prevention. People already diagnosed with type 2 diabetes should follow their doctor’s specific treatment plan. Pregnant women and people with other medical conditions should consult their healthcare provider before making major lifestyle changes.

Changes in blood sugar can take weeks to months to show up in standard tests. Most people in this study were re-evaluated after four years, so realistic expectations are that significant improvements take several months to a year of consistent lifestyle changes. Some people may see faster improvements, while others take longer.

Want to Apply This Research?

  • Track fasting blood glucose readings weekly (if you have a home monitor) or as recommended by your doctor, along with waist circumference monthly. Also log daily steps or exercise minutes and rate your adherence to Mediterranean diet patterns (vegetables, whole grains, olive oil use) on a 1-10 scale daily.
  • Set a specific, measurable goal such as: ‘Walk 30 minutes, 5 days per week’ and ‘Eat Mediterranean-style meals for dinner 6 days per week.’ Use the app to log these activities daily and receive reminders. Track one simple dietary change at a time—for example, adding one extra vegetable serving daily or switching to whole grain bread.
  • Create a monthly dashboard showing: (1) average daily steps/exercise minutes, (2) Mediterranean diet adherence score, (3) blood glucose readings if available, and (4) waist circumference trend. Review progress monthly and adjust goals if needed. Share results with your healthcare provider at regular check-ups to ensure your approach is working for your individual situation.

This research suggests associations between lifestyle factors and blood sugar improvement but does not constitute medical advice. Prediabetes and diabetes are serious medical conditions requiring professional diagnosis and monitoring. Before making significant dietary or exercise changes, especially if you have prediabetes, diabetes, or other health conditions, consult with your healthcare provider or a registered dietitian. Blood sugar monitoring should be done under medical supervision. Individual results vary based on genetics, overall health, and adherence to lifestyle changes. This article is for educational purposes and should not replace personalized medical guidance from your healthcare team.