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    Diabetes prevention

    Diabetes prevention: Stop diabetes before it starts.

    115.2 million American adults had prediabetes in 2023. In a landmark randomized trial, a year-long lifestyle program cut new cases of diabetes by 58%.

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    Ryan K. Hertel · heyitskenton

    The problem

    What we're up against.

    • More than four in ten adults.

      An estimated 115.2 million American adults, 43.5% of them, had prediabetes in 2023, and only 21.4% had been told so by a health professional.

    • Diabetes is already common.

      About 12% of Americans, 40.1 million people, have diabetes, diagnosed or not.

    • The costliest chronic disease.

      Diabetes cost America $412.9 billion in 2022, and care for people diagnosed with it accounts for one in four health care dollars.

    • A worldwide rise.

      One in nine adults worldwide, 589 million, were living with diabetes in 2024. Over four in ten don't know it, and 81% live in low- and middle-income countries.

    What works

    Proven, and ready to grow.

    • The landmark trial.

      In a randomized trial with 3,234 adults at high risk, a lifestyle program cut new cases of diabetes by 58%, against 31% for the drug metformin.

    • Benefits that last.

      Ten years on, new cases were still 34% lower in the lifestyle group, and the reductions held through twenty-one years.

    • Finland and China agree.

      A Finnish trial cut the risk of diabetes by 58%, and in China, six years of diet and exercise support delayed diabetes by a median of 3.96 years and added 1.44 years of life expectancy on average.

    • Across many trials.

      Pooling trials, 14.8% of people in diet and exercise programs developed diabetes, against 25.7% of those who weren't.

    • At national scale.

      England's national prevention program lowered the population's rate of new diabetes.

    What a family could fund

    Where the money goes furthest.

    • A year with a coach.

      Medicare's version is a one-year program with up to 22 sessions, and it paid at most $768 a person in 2024, when every target was met.

    • It may pay for itself.

      Even after a program cost of $518 an enrollee, one real-world study found an 88% chance it saved money within two years.

    • Programs closing for lack of money.

      More than 3,000 organizations adopted the program, but over half have since stopped, often because it didn't pay its way. Those that last lean on grants, in-kind support and charitable gifts.

    • Reach is the bottleneck.

      Medicare's program served 9,015 people in six years, against about 5.2 million who were eligible.

    • Proven in tribal communities.

      Native health programs ran it across 36 health care programs serving 80 tribes.

    Honest limits

    What money can't promise.

    • Few join, and many leave.

      Only 2.4% of adults with prediabetes in a national survey had ever taken part, and just 31.9% of in-person participants were still attending in the forty-fourth week.

    • Smaller outside trials.

      Real-world programs average a weight loss of about 4% after a year, and in England, the program's benefit was smaller than in trials.

    • Weight comes back.

      In the landmark trial, the lifestyle group partly regained the weight it lost, and the other groups' rates of new diabetes later fell to match.

    • Hearts not yet protected.

      Over twenty-one years, neither lifestyle change nor metformin reduced major heart attacks and strokes in the landmark trial.

    • Classes can't change a neighborhood.

      In a randomized experiment, a move to a lower-poverty neighborhood was linked to modest reductions in diabetes.

    Hard questions

    Asked and answered.

    1. You might ask

      Isn't this just personal responsibility?

      Ryan

      Partly, but much of the risk isn't chosen: in a randomized experiment, families offered a move to lower-poverty neighborhoods saw modest reductions in diabetes, with no classes at all. A program gives people the tools; the effort stays theirs.

    2. You might ask

      Why not a drug like metformin, or the new weight-loss medicines?

      Ryan

      Medicines help too. In the landmark trial, metformin cut new cases by 31%, against 58% for lifestyle change, and the newest drugs work only as long as people keep taking them.

    3. You might ask

      Do people actually finish these programs?

      Ryan

      Many don't. Those who stay do well: Medicare participants attended 18 sessions on average and lost 4.9% of their body weight.

    In the slider

    See what your fortune could do here.

    Diabetes prevention

    The slider prices this cause with these numbers:

    • Medicare paid at most $768 a person for a full year in the program in 2024, when every target was met.
    • The whole need is every American adult with prediabetes, about 115.2 million.
    • Outside trials the benefit is smaller, and providers say the payment doesn't cover their costs.
    Try it in the sliderTalk to Ryan

    More of the Blueprint

    Keep reading.

    17 more chapters on the way

    Back to Keep 100

    Sources

    Every number in this chapter, and where it came from.

    1. Source 1: National Diabetes Statistics Report (opens in a new tab)

      Centers for Disease Control and Prevention, 11 March 2026. Checked 16 October 2026.

    2. Source 2: Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin (Diabetes Prevention Program Research Group) (opens in a new tab)

      New England Journal of Medicine, 7 February 2002. Checked 16 October 2026.

    3. Source 3: Economic Costs of Diabetes in the U.S. in 2022 (Parker and others) (opens in a new tab)

      Diabetes Care, 1 January 2024. Checked 16 October 2026.

    4. Source 4: 11th edition of the IDF Diabetes Atlas: global, regional, and national diabetes prevalence estimates for 2024 and projections for 2050 (Genitsaridi and others) (opens in a new tab)

      The Lancet Diabetes & Endocrinology, 15 December 2025. Checked 16 October 2026.

    5. Source 5: Facts & figures (opens in a new tab)

      International Diabetes Federation, 7 April 2025. Checked 16 October 2026.

    6. Source 6: 10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study (Diabetes Prevention Program Research Group) (opens in a new tab)

      The Lancet, 14 November 2009. Checked 16 October 2026.

    7. Source 7: Long-term effects and effect heterogeneity of lifestyle and metformin interventions on type 2 diabetes incidence over 21 years in the US Diabetes Prevention Program randomised clinical trial (Knowler and others) (opens in a new tab)

      The Lancet Diabetes & Endocrinology, 28 April 2025. Checked 16 October 2026.

    8. Source 8: Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance (Tuomilehto and others) (opens in a new tab)

      New England Journal of Medicine, 3 May 2001. Checked 16 October 2026.

      The Finnish Diabetes Prevention Study, a randomized trial.

    9. Source 9: Morbidity and mortality after lifestyle intervention for people with impaired glucose tolerance: 30-year results of the Da Qing Diabetes Prevention Outcome Study (Gong and others) (opens in a new tab)

      The Lancet Diabetes & Endocrinology, 26 April 2019. Checked 16 October 2026.

      A trial in China, followed for thirty years.

    10. Source 10: Diet, physical activity or both for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk of developing type 2 diabetes mellitus (Hemmingsen and others) (opens in a new tab)

      Cochrane Database of Systematic Reviews, 4 December 2017. Checked 16 October 2026.

    11. Source 11: Population level impact of the NHS Diabetes Prevention Programme on incidence of type 2 diabetes in England: An observational study (McManus and others) (opens in a new tab)

      The Lancet Regional Health Europe, 29 May 2022. Checked 16 October 2026.

    12. Source 12: Medicare Diabetes Prevention Program (MDPP) Expanded Model (opens in a new tab)

      Centers for Medicare & Medicaid Services, 7 October 2026. Checked 16 October 2026.

    13. Source 13: Evaluation of the Medicare Diabetes Prevention Program (MDPP): Final Evaluation Report (opens in a new tab)

      Centers for Medicare & Medicaid Services, March 2025. Checked 16 October 2026.

    14. Source 14: Cost-effectiveness of the National Diabetes Prevention Program: A Real-world, 2-Year Prospective Study (Kuo and others) (opens in a new tab)

      Diabetes Care, 1 July 2025. Checked 16 October 2026.

      Insured adults in Michigan, compared with similar adults who didn't enroll.

    15. Source 15: How Organizations Sustain the National Diabetes Prevention Program: Real-world Strategies for Financing and Cost Control (Ritchie and others) (opens in a new tab)

      ADCES in Practice, 5 July 2026. Checked 16 October 2026.

    16. Source 16: Estimated number of eligible Part B beneficiaries for the Medicare diabetes prevention program at the county level and by urban-rural classification (Ng and others) (opens in a new tab)

      PLOS ONE, 10 November 2020. Checked 16 October 2026.

    17. Source 17: Translating the Diabetes Prevention Program into American Indian and Alaska Native communities (Jiang and others) (opens in a new tab)

      Diabetes Care, 28 December 2012. Checked 16 October 2026.

    18. Source 18: Prevalence and Correlates of Diabetes Prevention Program Referral and Participation (Venkataramani and others) (opens in a new tab)

      American Journal of Preventive Medicine, 17 January 2019. Checked 16 October 2026.

    19. Source 19: Retention Among Participants in the National Diabetes Prevention Program Lifestyle Change Program, 2012-2017 (Cannon and others) (opens in a new tab)

      Diabetes Care, 2 July 2020. Checked 16 October 2026.

    20. Source 20: How effective were lifestyle interventions in real-world settings that were modeled on the Diabetes Prevention Program? (Ali and others) (opens in a new tab)

      Health Affairs, January 2012. Checked 16 October 2026.

    21. Source 21: Referral to the NHS Diabetes Prevention Programme and conversion from nondiabetic hyperglycaemia to type 2 diabetes mellitus in England: A matched cohort analysis (Ravindrarajah and others) (opens in a new tab)

      PLOS Medicine, 27 February 2023. Checked 16 October 2026.

    22. Source 22: Effects of Long-term Metformin and Lifestyle Interventions on Cardiovascular Events in the Diabetes Prevention Program and Its Outcome Study (Goldberg and others) (opens in a new tab)

      Circulation, 23 May 2022. Checked 16 October 2026.

    23. Source 23: Neighborhoods, obesity, and diabetes: a randomized social experiment (Ludwig and others) (opens in a new tab)

      New England Journal of Medicine, 20 October 2011. Checked 16 October 2026.

    24. Source 24: Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension (Wilding and others) (opens in a new tab)

      Diabetes, Obesity and Metabolism, 19 May 2022. Checked 16 October 2026.

    25. Source 25: Medicare Diabetes Prevention Program: where are the suppliers? (Ritchie and others) (opens in a new tab)

      The American Journal of Managed Care, 1 June 2020. Checked 16 October 2026.