How the category emerged
In 1979–80 the U.S. National Diabetes Data Group and the World Health Organization labeled an in-between result on the oral glucose tolerance test "impaired glucose tolerance." In 1997 the American Diabetes Association lowered the fasting cutoff for diabetes from 140 to 126 mg/dL and created "impaired fasting glucose" for 110–125, then dropped the lower bound to 100 in 2003. The Diabetes Prevention Program (2002) showed that lifestyle changes cut new diabetes cases by 58%, turning prediabetes into a prevention target worldwide.
Cutoffs and risk
Fasting glucose of 100–125 mg/dL, a two-hour glucose tolerance result of 140–199, or an A1C of 5.7–6.4% all count as prediabetes. The CDC estimates about 98 million American adults—more than 1 in 3—have it, and most don't know. Roughly 5–10% progress to type 2 diabetes each year, and heart risk rises even before that. Add belly fat and high triglycerides and you may have metabolic syndrome.
Turning it around
Losing 5–7% of your weight and moving at least 150 minutes a week are the proven levers. A 10–15 minute walk after meals blunts glucose spikes, and strength training builds the muscle that soaks up sugar. Swap refined carbs and soda for vegetables and protein, eat them first, and aim for about seven hours of sleep. Intermittent fasting can help with weight loss, but consistency matters more than the method. Recheck glucose and A1C every one to two years.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Do I need medication for prediabetes?
- Usually lifestyle comes first; doctors may add metformin for high-risk people, such as those with a BMI over 35.
- Why is only my morning sugar high?
- It may be the "dawn phenomenon," when early-morning hormones prompt the liver to release extra glucose.
Sources reviewed: 2026-10-26
References
- American Diabetes Association. (2025). Standards of Care in Diabetes—2025. Diabetes Care, 48(Suppl 1).
- Knowler, W. C., et al. (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin (DPP). NEJM, 346(6), 393–403.
- 대한당뇨병학회. (2024). Diabetes Fact Sheet in Korea 2024.