Type 2 diabetes develops slowly as the body stops using insulin well, and in India it often starts younger and at a lower body weight than in many other countries. The good news is that it can frequently be delayed or prevented. Steady weight control, regular movement, better food choices and timely blood tests, especially if you have prediabetes, make a measurable difference.
Key takeaways
- About 11.4% of Indian adults have diabetes and another 15.3% have prediabetes, according to the national ICMR-INDIAB study.
- Asian Indians develop diabetes at lower BMI levels, so waist size matters: 90 cm or more for men and 80 cm or more for women is a warning sign.
- An HbA1c of 5.7% to 6.4% means prediabetes; 6.5% or higher suggests diabetes once confirmed.
- In an Indian trial, lifestyle changes cut the risk of progressing to diabetes by about 28% over three years.
- Early diabetes usually causes no symptoms, so testing is the only reliable way to know.
What type 2 diabetes is
Insulin is the hormone that moves sugar (glucose) from the blood into the body's cells. In type 2 diabetes, the cells respond poorly to insulin and the pancreas gradually cannot keep up. Blood sugar then stays high.
Over years, high blood sugar damages small and large blood vessels. This raises the risk of heart attack, stroke, kidney disease, vision loss, nerve damage and foot problems. Type 2 is by far the most common form of diabetes in adults.
How common it is in India
The ICMR-INDIAB study, published in The Lancet Diabetes & Endocrinology in 2023, tested more than 1.1 lakh adults across 31 states and union territories. It found that 11.4% had diabetes and 15.3% had prediabetes.
The same survey found that 28.6% had generalised obesity and 39.5% had abdominal obesity. Diabetes was more common in cities, but prediabetes was widespread in rural areas too, which suggests the problem is spreading.
Why Indians are at higher risk
The "thin-fat" Asian Indian phenotype
Many Indians carry more fat around the abdomen and internal organs, and less muscle, than people of the same weight from other backgrounds. This pattern is closely linked to insulin resistance.
The result is that diabetes can appear in someone who does not look overweight. For this reason Indian experts use lower cut-offs: a BMI of 23 to 24.9 kg/m² is considered overweight, and a 2025 India Obesity Commission revision kept 23 as the threshold where risk begins.
Waist size: a simple, powerful measure
For Asian Indians, a waist circumference of 90 cm or more in men or 80 cm or more in women indicates abdominal obesity. Measure at the level of your navel, standing relaxed, after breathing out.
Another easy check is waist-to-height ratio. If your waist is more than half your height, your risk is likely raised.
Other risk factors
| Risk factor | Why it matters |
|---|---|
| Family history (parent or sibling) | Shared genes and habits raise risk |
| Age over 35 | Risk climbs with each decade |
| Physical inactivity | Muscles use less glucose |
| Diets high in refined carbs and sugary drinks | Large, repeated sugar spikes |
| Gestational diabetes or PCOS | Strong predictors of later type 2 |
| High blood pressure or abnormal cholesterol | Often travel together with insulin resistance |
| Poor sleep, chronic stress, smoking | Worsen insulin sensitivity |
Understanding the numbers
Diabetes and prediabetes are diagnosed with blood tests. The table below uses American Diabetes Association cut-offs, which are widely used by Indian doctors and guidelines.
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| HbA1c | Below 5.7% | 5.7% to 6.4% | 6.5% or higher |
| Fasting plasma glucose | Below 100 mg/dL | 100 to 125 mg/dL | 126 mg/dL or higher |
| 2-hour OGTT glucose | Below 140 mg/dL | 140 to 199 mg/dL | 200 mg/dL or higher |
A single abnormal result is usually repeated on another day before a diagnosis is made. Anaemia, some haemoglobin variants and recent blood loss can make HbA1c less reliable, which is common in India, so your doctor may use more than one test.
Who should get tested
The ADA advises testing all adults from age 35. Testing earlier makes sense for Asian adults with a BMI of 23 or more and at least one other risk factor. If results are normal, repeating at least every three years is reasonable; if you have prediabetes, check yearly.
Early signs to watch for
Most people with early type 2 diabetes or prediabetes feel completely well. When symptoms appear, they may include:
- Increased thirst and frequent urination, including at night
- Tiredness that is hard to explain
- Blurred vision
- Unplanned weight loss
- Slow-healing cuts, frequent skin, gum or urinary infections
- Tingling or numbness in the feet
- Dark, velvety skin patches on the neck or armpits (a sign of insulin resistance)
If you notice any of these, ask for a blood sugar test rather than waiting for your next routine check-up.
How to prevent or delay type 2 diabetes
The evidence from India
The Indian Diabetes Prevention Programme enrolled 531 adults in Chennai who already had impaired glucose tolerance. Over three years, 55% of the control group developed diabetes, compared with about 39% in the lifestyle group. That is a relative risk reduction of roughly 28.5%. Participants were not asked to make dramatic changes; the advice focused on regular walking and simple diet improvements.
Food: practical changes for Indian meals
- Fill half the plate with vegetables, a quarter with protein (dal, legumes, paneer, eggs, fish or chicken) and a quarter with grains.
- Choose whole grains such as millets, whole wheat, brown or parboiled rice, and keep portions of white rice and maida modest.
- Cut back on sugary tea and coffee, soft drinks, packaged juices and sweets.
- Limit fried snacks and reuse of frying oil.
- Eat whole fruit rather than juice, and include nuts and seeds in small amounts.
Movement
Aim for at least 150 minutes of moderate activity each week, such as brisk walking, cycling or swimming, as WHO advises. Add muscle-strengthening exercise twice a week. A 10 to 15 minute walk after meals can help blunt sugar spikes.
Weight, sleep and tobacco
If you are overweight, losing even a modest amount of weight improves insulin sensitivity. Aim for 7 to 8 hours of sleep, manage stress, and stop smoking or chewing tobacco. If you drink alcohol, keep it limited.
Medicines
Some people with prediabetes and high risk may be offered medicine by their doctor. Never start, stop or change diabetes medicine on your own, and be wary of products promising to "reverse" diabetes.
When to see a doctor
See a doctor soon if you have:
- Constant thirst, frequent urination, or weight loss without trying
- A fasting sugar or HbA1c result in the prediabetes or diabetes range
- A foot wound, blister or colour change that is not healing
- Sudden blurred vision
Seek emergency care, by calling 108 or 112, if someone with diabetes is confused, very drowsy, breathing fast, vomiting repeatedly, or has fainted. These can signal dangerously high or low blood sugar.
Frequently asked questions
Can prediabetes be reversed?
For many people, yes. Weight loss, regular activity and better eating can return blood sugar to the normal range and lower the chance of developing diabetes. It does not work for everyone, so keep testing yearly even if your numbers improve.
Why do slim Indians get diabetes?
Many Indians store fat around the abdomen and internal organs even at a normal BMI, and have relatively less muscle. This hidden fat drives insulin resistance. That is why waist size and lower BMI cut-offs are used for South Asians.
Is eating sugar the cause of diabetes?
Sugar alone does not cause type 2 diabetes, but sugary drinks and frequent sweets add calories and cause sugar spikes that raise risk over time. Overall diet quality, weight, activity and genes all play a part.
Is rice bad for people at risk of diabetes?
Rice does not need to be eliminated. Keeping portions moderate, choosing less-polished varieties, and pairing it with plenty of vegetables, dal and protein can reduce its effect on blood sugar.
How often should I check my HbA1c if I have prediabetes?
Once a year is the usual advice, or sooner if your doctor asks. If you already have diabetes, your doctor will set a schedule, often every three to six months.
Sources
- American Diabetes Association: Diagnosis
- American Diabetes Association: Prediabetes
- WHO: Diabetes fact sheet
- ICMR-INDIAB-17 national metabolic NCD study, Lancet Diabetes & Endocrinology 2023
- Ramachandran A et al. The Indian Diabetes Prevention Programme, Diabetologia 2006
- Misra A et al. Revised definition of obesity in Asian Indians living in India, 2025