What Prediabetes Actually Means — And What to Do About It

What we checked — and how we reached this conclusion

We reviewed the primary clinical trial literature on prediabetes reversal, the diagnostic criteria used by major diabetes research bodies, and the peer-reviewed data on specific dietary and lifestyle interventions. We did not simply restate official guidelines — where the trial evidence is stronger or more nuanced than the standard talking points, we followed the evidence.

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  Diagnostic thresholds confirmed The exact fasting glucose, HbA1c, and oral glucose tolerance test values that define prediabetes were verified against the American Diabetes Association's Standards of Care (2025) and the original NHANES data that established these cut-points.
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  Diabetes Prevention Program trial reviewed The landmark NIH-funded DPP randomized controlled trial (3,234 participants, 3-year follow-up) confirmed that lifestyle intervention reduced Type 2 diabetes incidence by 58% — and that this effect was replicated in the 10-year DPPOS follow-up study.
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  Dietary evidence weighed independently We reviewed meta-analyses on low-carbohydrate, Mediterranean, and low-fat diets for prediabetes. All three show meaningful benefit; the evidence does not support a single "best" diet, but does strongly support reducing refined carbohydrates and added sugars as the highest-leverage dietary change.
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  Metformin evidence assessed The DPP also tested metformin against lifestyle change. Lifestyle intervention outperformed metformin in the trial overall, though metformin showed stronger comparative benefit in younger participants and those with higher BMI. This nuance is absent from most lay coverage.

There's more than one right path — here's how to choose yours

Where you are in the prediabetes range, your current weight, and your lifestyle constraints all affect which approach will move the needle fastest for you.

What people try first that doesn't actually help

The prediabetes space is full of products and strategies that feel proactive but have little or no evidence behind them — and a few that can actively delay the changes that do work.

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  Blood sugar supplements (berberine, cinnamon, chromium, etc.) — Some of these show modest effects in small studies, but none have been tested in the kind of large, long-term trials that established lifestyle change works. Spending money on supplements while delaying dietary and exercise changes is the wrong trade-off when the window to act is now.
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  Eating "healthy" without specifically reducing refined carbohydrates — A diet that's rich in whole grains, fruit juice, and low-fat products can still produce persistent blood sugar elevation. The glycemic load of your diet matters specifically, not just its general healthfulness. People are often surprised that "clean eating" doesn't move their numbers.
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  Treating prediabetes as "almost not a problem" — Roughly 84 million American adults have prediabetes, and the vast majority haven't been told. The diagnosis is easy to dismiss because you don't feel sick. But every year of elevated blood sugar causes measurable damage to blood vessels and nerves, and the longer the elevation continues, the harder reversal becomes.
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  Waiting to retest without changing anything — Some doctors retest in a year without giving specific guidance. If nothing changes in your diet or activity level, the retest will almost always show the same or worse numbers. A retest only means something if something has changed in the year prior.