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Lifestyle Beats Metformin: 21-Year Data Shows Lifestyle Cuts Multimorbidity Risk

By the GlycemicWise Data Editorial Team · Published 2026-09-03 · Last reviewed 2026-09-03 · Nutrition Science · 6-8 min read · Dietary reference only

A 2026 JAMA analysis of the 21-year Diabetes Prevention Program found intensive lifestyle changes cut multimorbidity risk by 21% in prediabetes — metformin showed no benefit over placebo.

21-Year Follow-Up

In August 2026, researchers from Washington University published in JAMA a landmark analysis of the Diabetes Prevention Program (DPP) and its long-term follow-up (DPPOS). The DPP, which began in 1996, randomized adults with prediabetes into three groups: intensive lifestyle intervention, metformin, or placebo. The new analysis followed 1,173 participants for up to 21 years to answer a question no earlier trial had: can these interventions prevent not just diabetes, but the cluster of chronic diseases that often accompany it?

The Multimorbidity Result

Multimorbidity — having two or more chronic conditions such as hypertension, diabetes, heart disease, and cancer simultaneously — affected 85 percent of participants over the 21-year follow-up. Compared with placebo, the intensive lifestyle group had a 21 percent lower risk of developing multimorbidity, and a 25 percent lower risk of accumulating three or more chronic conditions. The lifestyle group also had a 43 percent lower risk of developing high-cost chronic disease combinations. The most striking secondary finding: metformin showed no significant benefit over placebo for multimorbidity prevention — essentially, the same as taking nothing.

What the Lifestyle Intervention Looked Like

The lifestyle arm was not extreme. It combined a calorie-controlled diet (less than 25 percent of calories from fat), at least 150 minutes of moderate physical activity per week, and a goal of losing 7 percent of body weight. Participants met with trained lifestyle coaches and attended regular group sessions. The 21-year data now show that this modest, structured program — not a drug — was the intervention that reduced the overall chronic disease burden decades later.

Why Multimorbidity Matters for Blood Sugar

People with prediabetes and diabetes rarely have only one metabolic problem. Insulin resistance coexists with hypertension, dyslipidemia, fatty liver, and cardiovascular risk. The JAMA analysis found that developing diabetes further increased multimorbidity risk by 33 percent. This means preventing diabetes is not just about glucose — it is about preventing a cascade of interconnected conditions. The DPP lifestyle intervention appears to slow the entire cascade, not just the glucose component.

The Practical Translation

You do not need a research protocol to apply the DPP pattern. The core elements are: reduce refined carbohydrates and added fats (especially from ultra-processed foods), move 30 minutes most days, and aim for gradual weight loss of 5 to 7 percent if you carry excess weight. On GlycemicWise, the food pages show glycemic load per serving so you can identify the carbohydrate swaps that keep the calorie reduction sustainable without feeling restrictive.

Key Points to Remember

The 2026 JAMA analysis of the DPP's 21-year follow-up delivers a clear message: structured lifestyle change prevents chronic disease multimorbidity in people with prediabetes, while metformin did not outperform placebo. The effect was large and long-lasting. For diabetes prevention, the diet-and-activity package remains the most evidence-backed intervention available.

Dietary reference — not medical advice. Information provided for educational purposes.