Prediabetes, precisely
A laboratory finding with no symptoms, defined slightly differently by the two bodies that define it. Both definitions are below.
Nothing here can diagnose you, and nothing here is a treatment plan. Blood glucose results are interpreted by a doctor alongside your history, your symptoms and a repeat test — a single number on a screen is not a diagnosis. If any reading concerns you, or if you feel unwell, see a doctor rather than a website.
The published ranges
| Result | Published value | Same value in mmol/L |
|---|---|---|
| Fasting plasma glucose — at least 8 hours with no food | ||
| Normal | 99 mg/dL or below | 5.5 mmol/L or below |
| Prediabetes | 100 to 125 mg/dL | 5.6 – 6.9 mmol/L |
| In the diabetes range | 126 mg/dL or above | 7.0 mmol/L or above |
| 2 hours into a 75 g oral glucose tolerance test | ||
| Normal | 139 mg/dL or below | 7.7 mmol/L or below |
| Prediabetes | 140 to 199 mg/dL | 7.8 – 11.0 mmol/L |
| In the diabetes range | 200 mg/dL or above | 11.1 mmol/L or above |
| HbA1c | ||
| Normal | below 5.7% | — |
| Prediabetes | 5.7% to 6.4% | — |
| In the diabetes range | 6.5% or above | — |
| Random (any time of day) | ||
| In the diabetes range | 200 mg/dL or above with the classic symptoms of high blood glucose | 11.1 mmol/L or above |
A result in the diabetes range is not a diagnosis. Published criteria require confirmation — normally a repeat of the same test on a separate day, unless someone has unmistakable symptoms with a clearly raised glucose. Your doctor makes that call, not a chart.
Source: American Diabetes Association, Standards of Care in Diabetes — Diagnosis and Classification of Diabetes. Diabetes Care 2025;48(Suppl. 1):S27–S49. Link
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health — Diabetes Tests & Diagnosis. Link
The one number the two bodies disagree on
Prediabetes starts at a fasting glucose of 100 mg/dL
5.6 mmol/L · American Diabetes Association
The ADA sets the lower edge of impaired fasting glucose at 100 mg/dL, which classifies a much larger group of people as having prediabetes.
Impaired fasting glucose starts at 110 mg/dL
6.1 mmol/L · World Health Organization / IDF
WHO kept the higher cut-off. A fasting result of 105 mg/dL is prediabetes by American criteria and normal by WHO criteria — same blood, different rulebook.
Both figures are real and both are current. Which one your report uses depends on which guideline your laboratory or doctor follows. Every threshold above 126 mg/dL — the diabetes threshold itself — is identical in both.
This matters more in practice than it looks on paper: a very large number of people sit between 100 and 110 mg/dL fasting, and whether their report is flagged depends on which guideline their laboratory follows.
WHO's own terminology
WHO does not use the word "prediabetes" in its diagnostic criteria. It describes two separate states, which can occur together or on their own.
| Category | Fasting plasma glucose | 2 h after a 75 g glucose load |
|---|---|---|
| Diabetes | 7.0 mmol/L (126 mg/dL) or above | 11.1 mmol/L (200 mg/dL) or above |
| Impaired fasting glucose (IFG) | 6.1 – 6.9 mmol/L (110–125 mg/dL) | below 7.8 mmol/L (140 mg/dL), if measured |
| Impaired glucose tolerance (IGT) | below 7.0 mmol/L (126 mg/dL) | 7.8 – 11.0 mmol/L (140–199 mg/dL) |
WHO also accepts a random plasma glucose of 11.1 mmol/L (200 mg/dL) or above, in the presence of symptoms, and — since the 2011 consultation — an HbA1c of 6.5% or above. WHO is explicit that an HbA1c below 6.5% does not rule diabetes out.
Source: World Health Organization / International Diabetes Federation. Definition and diagnosis of diabetes mellitus and intermediate hyperglycaemia: report of a WHO/IDF consultation. Geneva: WHO, 2006. Link
Why the Indian numbers are so large
The ICMR-INDIAB national survey estimated 136 million adults in India with prediabetes, alongside 101 million with diabetes. Prediabetes produces no symptoms whatsoever, so essentially all of those 136 million were found by measurement rather than because anyone felt something was wrong.
South Asians also tend to develop glucose problems at lower body weights and younger ages than European populations, which means the familiar visual cues are unreliable here. A normal weight is a weaker reassurance in India than international charts imply.
Source: Anjana RM, Unnikrishnan R, Deepa M, et al. Metabolic non-communicable disease health report of India: the ICMR-INDIAB national cross-sectional study (ICMR-INDIAB-17). Lancet Diabetes Endocrinol 2023;11(7):474–489. Link
What this page will not tell you
It will not tell you how to reverse it. It publishes no diet plan, no herbal remedy, no supplement, no "seven foods that cure it" and no timeline, because prediabetes is a clinical finding about a specific person and none of those things can be prescribed by a web page. The internet is full of confident promises on this exact search term, and confidence is not evidence.
What is genuinely worth doing with a prediabetes result is taking it to a doctor, who can look at the rest of your results, decide whether and when to repeat the test, and talk through what applies to you. That is a duller answer than the ones ranking above this page. It is also the honest one.
PeakForm is a training and accountability programme. It is not a treatment for diabetes or prediabetes, it is not a substitute for your doctor's advice, and nothing on this site should be acted on before speaking to one.
Common questions
What blood sugar level is prediabetes?
Is prediabetes the same as diabetes?
Does prediabetes have symptoms?
Can prediabetes be reversed?
Criteria from the ADA Standards of Care, NIDDK and the WHO/IDF 2006 consultation. Prevalence from ICMR-INDIAB (Lancet Diabetes Endocrinol 2023). General information only — NOT medical advice, and never a diagnosis. Only a doctor can interpret your results and diagnose or treat diabetes. If a reading concerns you, see a doctor rather than a website. Every threshold, equation and glycemic index value used on this site is listed with its publication on the data & method page.