Twenty-one years after its launch, the U.S. Diabetes Prevention Program remains a landmark study. The latest results are in: People with prediabetes who made intensive lifestyle changes reduced their risk of developing Type 2 diabetes by 58 percent—nearly twice as effective as metformin, which lowered risk by 31 percent. And the benefits lasted more than two decades.
The Landmark Clinical Trial
In the U.S. Diabetes Prevention Program trial, participants were randomly assigned to one of three groups: an Intensive Lifestyle Intervention, metformin (850 milligrams twice daily), or a placebo group.The Intensive Lifestyle Intervention group worked one-on-one with case managers to achieve at least 7 percent body weight loss through dietary changes and at least 150 minutes of moderate-intensity physical activity per week.
The dietary approach focused on lowering total fat intake to under 25 percent of daily calories. If participants didn’t lose weight by reducing fat, calorie restrictions were added. The program later transitioned to group classes to support long-term progress.
Outdated Interventions
While the Diabetes Prevention Program offers robust evidence and important long-term follow-up, its approach reflects the nutritional science of the mid-1990s.That’s a key limitation of long-term trials, Gibson noted.
“The core message was designed to be simple and achievable based on the understanding at the time: reduce total fat and calories, move more, lose weight,” she said.
Medical science evolves, so by the time a 21-year follow-up is reached, the original interventions may no longer align with current understanding.
“With what we now understand about metabolic health, the role of ultra-processed foods, and the importance of the gut microbiome, I think a more holistic dietary pattern might deliver even greater benefits,” Gibson said.
Beyond Weight Loss
The Diabetes Prevention Program emphasized weight loss as a primary goal, but this focus can sometimes obscure other meaningful improvements, Gibson said.“I’ve seen patients dramatically improve their metabolic risk markers through dietary changes or increased physical activity, with little movement on the scales,” she noted.
Shifting the focus from weight to behavior can empower people and help prevent the frustration of doing everything right without seeing results on the scale.
Health-focused behaviors often improve insulin sensitivity, offer better control of blood sugars, reduce visceral fat, and improve mental health.
Kimberlain said that exercise may help shrink abdominal fat, a key driver of metabolic risk, without leading to major shifts in total body weight.
- Choose Healthy Fats: Include more nuts, seeds, avocado, and olive oil. These fats are typically part of a Mediterranean-style diet, which has been shown to help manage Type 2 diabetes through several mechanisms, including its anti-inflammatory and antioxidant effects.
- Cut Ultra-Processed Foods: Reduce refined carbs, sugary drinks, and packaged snacks to support more stable blood sugars and lower chronic disease risk.
- Include Lean Proteins: Add lean protein sources to promote satiety, blood sugar stability, and muscle maintenance.
A More Powerful Approach
If weight loss isn’t the only goal, what else works in preventing or managing Type 2 diabetes?The answer starts with personalization, Gibson said.
“While some principles apply broadly, the most important and effective aspects for each person will be individual to their unique situation,” she said.
1. Improve Diet Quality
Focus on whole, minimally processed foods, and eat more fiber. Fiber slows the absorption of sugar, helps reduce insulin resistance, and may lower levels of inflammation linked to body fat.2. Strengthen Your Gut Health
An imbalanced microbiome can reduce the body’s ability to use insulin properly and make it harder to control blood sugar.Healthy gut bacteria help break down fiber into short-chain fatty acids, which support the gut lining, reduce inflammation, and help with insulin production. However, when the balance of bacteria is off, the gut barrier becomes weaker. This allows harmful substances to leak into the body, triggering chronic inflammation, which is common in diabetes. Changes in the microbiome also affect gut hormones and how the body handles sugar and fat.
3. Prioritize Sleep and Stress Management
Getting enough sleep is important for managing and preventing Type 2 diabetes.Many people with diabetes have trouble sleeping, which can make it harder to control blood sugar and affect their mood and quality of life. On the flip side, not sleeping well—especially with conditions such as sleep apnea—can raise the risk of developing diabetes. Stress from modern life often affects sleep, adding to the problem.
“We also need to apply behavioral science, consider the full range of lifestyle medicine, and listen to our clients’ lived experiences,” Gibson said. She added that it’s essential to shape environments where healthy choices feel easier and more realistic to maintain over time.
Still, one of the most enduring takeaways from the Diabetes Prevention Program is the power of structured lifestyle support. Kimberlain said the behavior-change techniques—coaching, accountability, and ongoing education—remain foundational, whether the focus is on fat reduction or dietary quality.
