Prediabetes: A Window of Opportunity, Not a Label

The big picture

According to the International Diabetes Federation (IDF) Diabetes Atlas, 589 million adults aged 20–79 were living with diabetes worldwide in 2024, about 1 in 9 adults. The projection for 2050 is 853 million, and 252 million people are still undiagnosed. In Türkiye, adult prevalence of diabetes is above 16% (roughly 9.6 million people).

Prediabetes is the in-between zone where blood sugar is above normal but not yet in the diabetes range: a fasting glucose of 100–125 mg/dL, or an HbA1c (a blood test reflecting average sugar over recent months) of 5.7–6.4%. In Türkiye’s TURDEP-II study, impaired fasting glucose (borderline-high fasting sugar) was 14.7% and impaired glucose tolerance (sugar staying high after a sugar load) 7.9%. The presentation reads this high frequency as a sign that the period in which lifestyle change works best is wide.

A label, or an opportunity?

The presentation also includes a two-sided debate. Critics say a prediabetes diagnosis can lead to unnecessary medication, to people labeling themselves as 'diabetic', and to stigma. Supporters say it is a high-risk state for type 2 diabetes and cardiovascular disease, and that lifestyle intervention can prevent or delay diabetes.

The common ground: prediabetes should be explained not as a disease label but as a window of opportunity. What happens in the body fits this. When insulin resistance (cells responding less well to insulin) increases, β-cells (the cells that release insulin) secrete more to keep sugar in balance; when that compensation falls short, sugar begins to rise. Lifestyle change in the early stage can bring sugar back to the normal range; as β-cell loss progresses, medication becomes necessary.

What did the large trials show?

The prevention trials tell a similar story. In the US Diabetes Prevention Program (DPP) trial, an intensive program with a weight-loss goal of at least 7% and at least 150 minutes of activity per week reduced progression to diabetes by 58%; in the medication arm the figure was 31%. The Finnish study also reported a 58% reduction with lifestyle. In the 30-year follow-up of China’s Da Qing study, the onset of diabetes was delayed by a median of 3.96 years.

Much of the effect is explained by weight loss, but in the Indian study, lifestyle reduced risk by 28.5% even without meaningful weight loss. In one meta-analysis, blood sugar returned to normal in a share of participants: 20% at year 2 and 52% at year 6. These trials were run under ideal conditions, however, and real-world effects may be smaller: across 22 programs in 11 countries, the average weight loss was 2.3 kg.

What does 'remission' mean?

Type 2 diabetes is described as a progressive disease; a growing need for medication over time is not 'diet failure' but β-cell insufficiency. The word 'remission' also deserves a careful reading. By the 2021 definition of the American Diabetes Association and the European Association for the Study of Diabetes (ADA/EASD), remission means an HbA1c below 6.5% at least 3 months after glucose-lowering medication has been stopped. The presentation stresses that this is not a 'cure' and that follow-up continues.

The best-known study is DiRECT (Diabetes Remission Clinical Trial): people diagnosed within the previous 6 years received structured weight management in primary care. Remission at month 12 was 46% (control 4%), and 86% among those who lost 15 kg or more. At year 5 it was 27% (control 4%). The 'twin cycle' hypothesis, which proposes that fat accumulating in the liver and pancreas impairs β-cell function, tries to explain this.

The chance of remission is not the same for everyone: higher in an overweight person with disease of short duration, lower in a lean person with long-standing disease who uses insulin. Although the definition mentions stopping medication, the decision to reduce, change or stop medication always rests with the physician.

Small steps in practice

The trials' targets are not flashy: weight loss of at least 7% in the DPP and at least 5% in the Finnish study (5–6 kg for someone weighing 90 kg), and at least 150 minutes of activity a week, such as brisk walking. A 10–15 minute walk after each main meal is noted to reduce the post-meal rise in sugar. There is no single ideal diet; from among the Mediterranean, DASH (Dietary Approaches to Stop Hypertension), plant-based and lower-carbohydrate eating patterns, the one a person can sustain the longest is chosen.

A plate method for Turkish cuisine: half a plate of olive-oil vegetable dishes or salad, a quarter plate of legumes, fish, chicken or eggs, and a quarter plate of bulgur pilaf or whole-grain bread. Water instead of sugary drinks, unsweetened tea instead of sweetened tea, whole fruit instead of fruit juice. Lifestyle does not replace medication; it works alongside it, and portions should be set with a dietitian and a physician according to the person’s medications and needs.