Pre Diabetes? How To Stop It From Progressing

Woman using a blood glucose meter at home — Photo: New Africa / Shutterstock

Millions of Americans walk around with blood sugar high enough to put them on the road to type 2 diabetes, and most of them have no idea.

Quick Take

Endocrinologist Dr. Alice Cheng explains that prediabetes means blood sugar is elevated but has not yet crossed the line into full diabetes.
Official diagnosis thresholds rely on fasting blood sugar or an A1C blood test measuring sugar attached to red blood cells.
Research shows lifestyle changes and, in some cases, medication can meaningfully cut the chance of progressing to diabetes.
Not everyone with prediabetes develops full diabetes, and different health groups use slightly different cutoff numbers.

What Counts As Prediabetes, And Why The Numbers Matter

Dr. Alice Cheng, an endocrinologist and professor of medicine at the University of Toronto, breaks down how doctors define diabetes itself. A fasting blood sugar of seven millimoles per liter or higher, or an A1C test showing how much sugar sticks to red blood cells, confirms a diabetes diagnosis. Prediabetes sits just below that line, a warning zone rather than the disease itself.

The American Diabetes Association defines prediabetes as an A1C between 5.7 and 6.4 percent, or a fasting glucose between 100 and 125 milligrams per deciliter. Diabetes Canada draws its own line, using a fasting glucose range of 6.1 to 6.9 millimoles per liter and an A1C of 6.0 to 6.4 percent, a narrower and higher-risk band. The numbers differ slightly, but the warning is the same.

Why Catching It Early Changes The Outcome

Dr. Cheng tells viewers that people with prediabetes face a higher risk of moving forward into full diabetes, but that outcome is not locked in. She explains the risk “is achievable through lifestyle modifications or… medication,” framing prediabetes as a stage where action still matters. The message is simple: a diagnosis is a signal to act, not a sentence.

That message lines up with decades of research. The landmark Diabetes Prevention Program found that an intensive lifestyle push, built around modest weight loss and regular activity, cut the rate of progression to type 2 diabetes by 58 percent over three years. Metformin, a common diabetes medication, reduced progression by 31 percent over the same period. Both routes work, but lifestyle change outperformed the pill.

The Lifestyle Changes That Actually Move The Needle

The American Diabetes Association’s clinical guidance spells out what worked in those trials: losing roughly 5 to 7 percent of body weight and getting at least 150 minutes of moderate activity, like brisk walking, every week. People with prediabetes should get referred to a structured lifestyle program and tested annually to track whether their blood sugar is climbing or holding steady. These aren’t vague suggestions. They’re the exact habits studied and proven in large trials.

Lifestyle intervention also beat metformin head to head in broader reviews of the evidence. A pooled analysis of 23 trials found lifestyle changes lowered the risk of progressing to diabetes by 22 percent compared to no intervention. Metformin remains a useful backup, especially for people who struggle to sustain diet and exercise changes, but it is not the frontline weapon doctors reach for first.

Not every person with prediabetes ends up with diabetes. Diabetes Canada notes plainly that individuals don’t necessarily progress along that path, and there is no single worldwide agreement on where impaired fasting glucose begins. That nuance matters because it means a prediabetes diagnosis is a call to adjust habits, not a guaranteed countdown clock. The science backs a clear, common-sense conclusion: catch it early, change the daily routine, and the odds shift back in your favor.