Published Aug 08, 2026 | 7:00 AM ⚊ Updated Aug 08, 2026 | 7:00 AM
Synopsis: We Indians, and South Asians in general, have fewer of what are called small adipocytes, or small fat cells, on the abdominal wall. When we eat excess food, especially junk food that is high in carbohydrates and fat, it gets converted into fat. That fat first tries to stay in the abdominal wall.
India has changed dramatically over the past few decades. Economic growth, urbanisation, changing diets and sedentary lifestyles have transformed how Indians live, work and eat. But according to one of the country’s leading diabetologists, those changes have also reshaped the nation’s metabolism.
A new 25-year review has identified abdominal obesity as the fastest-growing metabolic risk in urban India. But for Dr V Mohan, a Padma Shri awardee and chairman of Dr Mohan’s Diabetes Specialities Centre and co-author of the review, the findings are part of a much larger story. It stretches from famine and the Green Revolution to economic liberalisation, the IT boom and the rise of ultra-processed foods.
In this interview with South First, Dr Mohan explains why Indians develop diabetes at younger ages, why waist circumference may matter more than Body Mass Index (BMI), how new obesity drugs are changing treatment, and why he believes reversing India’s metabolic crisis will require changes far beyond individual lifestyle choices.
Q. Your study found that abdominal obesity has increased faster than diabetes, hypertension and general obesity in urban India over the past 25 years. Were you surprised by the magnitude of this finding?
A: We were not completely surprised because we already had data from the ICMR-INDIAB study, the CURES study and several other studies showing that abdominal obesity is increasing very rapidly in our population.
Abdominal obesity is driven largely by junk food, excess calories and lack of physical activity. But we as Indians are particularly prone to develop abdominal obesity, especially intra-abdominal fat.
Now, we understand the mechanism behind it. We as Indians, and South Asians in general, have fewer of what are called small adipocytes, or small fat cells, on the abdominal wall. When we eat excess food, especially junk food that is high in carbohydrates and fat, it gets converted into fat. That fat first tries to stay in the abdominal wall.
For white Europeans, there are many more of these small adipocytes. They first fill those up. It is like wearing an extra suit on your body. The fat is not going inside.
For us, those fat cells get saturated very quickly. Then the fat enters the abdomen, where it becomes visceral fat. That increases the waist circumference and leads to abdominal obesity.
That is why measuring waist circumference is such an excellent indicator. If the waist is more than 90 centimetres in men and 80 centimetres in women, abdominal obesity is present.
What is worrying is that we are now seeing this not only in adults but also in adolescents and children. We find even six-year-olds and eight-year-olds coming with a big paunch because they are eating so much junk food. Food bought outside is very high in calories, sugar, carbohydrates and unhealthy fats. Couple that with physical inactivity because children are not playing outside anymore, and it becomes a double whammy.
Q. Why is fat around the waist considered much more dangerous than fat elsewhere in the body? What actually happens inside the body?
A: The fat under the skin on the abdominal wall is what we call subcutaneous fat. That is relatively inert. I often compare it to wearing an extra coat during winter. It is there, but it is not causing much harm internally.
The problem starts when fat goes inside the abdomen. That is visceral fat or intra-abdominal fat.
The first place it goes to is the liver. Once fat accumulates there, the liver becomes insulin resistant, meaning insulin cannot work properly. That eventually leads to diabetes.
Then the fat starts accumulating around blood vessels and around the heart. We call this ectopic fat because it is sitting where fat is not supposed to be.
This type of fat is metabolically active and highly inflammatory. Once it produces inflammation, it is almost like having COVID constantly. There is continuous inflammation, and that increases the risk of diabetes, hypertension, heart attacks, stroke and even some cancers.
That is why visceral fat is much more dangerous than the fat under the skin.
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Q. India has often been described as the home of the ‘thin-fat Indian’, where people appear lean but carry excess abdominal fat. Why are Indians particularly prone to this, and has the problem become worse over time?
A: Yes, there are three or four reasons.
First, genetically we seem to be more prone to it. One factor, particularly in parts of South India, has been consanguineous marriages or marriages within the extended family. Historically, people married first cousins or other close relatives to keep wealth within the family and because they knew the family well.
What happens is that if a family carries genes that increase the risk of diabetes, insulin resistance or abdominal obesity, those genes keep getting reinforced over generations.
Second, we have to look at India’s history. Earlier, we had starvation and undernutrition. During the British period, there were major famines, including the Bengal Famine and the Madras Famine. Even outside those events, people could not afford enough food. Until the 1960s, India was importing food from the United States.
Then came the Green Revolution. We started growing enough wheat and rice. After that came the economic liberalisation in 1991, when India opened up its economy. People’s incomes improved. They could afford more food, but they also became less physically active. Instead of walking or cycling, they started buying scooters and cars.
Then came the IT revolution. Young people began working on American schedules, sleeping less, disrupting their circadian rhythm, and becoming even more sedentary.
Another important factor is what we call the thin-fat phenotype. When mothers are undernourished during pregnancy, they give birth to smaller babies. Those children already carry a tendency to store fat internally. Later, when they grow up in an environment with abundant food, they gain weight rapidly and develop diabetes, hypertension and heart disease much earlier than Europeans.
That is why Indians get heart attacks in their 20s and 30s. In Europe, you usually see them after the age of 50 or 60. Similarly, type 2 diabetes develops much earlier here.
Finally, we are also a carbohydrate-heavy nation. Excess carbohydrates are converted into glucose and then into fat, which further contributes to abdominal obesity.
The encouraging part is that many of these factors are modifiable. If people reduce refined carbohydrates, eat more protein and fibre, become physically active and sleep properly, much of the insulin resistance and obesity can be reversed. Today, we also have excellent medicines that can help reduce body weight and liver fat significantly.
Q. Your ICMR-INDIAB study found an interesting pattern. Punjab and Haryana have abdominal obesity levels close to Kerala, yet Kerala’s diabetes prevalence is almost twice as high. What explains these differences between states?
A: You’re absolutely right. The ICMR-INDIAB study showed huge differences in diabetes prevalence across India.
Kerala, Goa, and Puducherry had the highest prevalence, around 25 to 26 percent of adults. Punjab also had high abdominal obesity and very high cholesterol because of dietary habits, but diabetes prevalence was somewhat lower.
One reason may be that physical activity is still relatively higher in Punjab and Haryana. Many of India’s athletes and sportspeople come from those states.
On the other hand, diabetes prevalence was much lower in states such as Uttar Pradesh, Bihar and several northeastern states like Assam, Meghalaya, Mizoram and Nagaland. We also saw lower rates in economically less developed states such as Jharkhand and Chhattisgarh.
When we visited rural Jharkhand, many people had a Body Mass Index of 16 or 18. They were extremely thin. In some communities, we found virtually no diabetes because people were still undernourished.
The southern states experienced economic growth earlier. Kerala benefited from remittances from the Middle East, while Bengaluru, Hyderabad and Chennai became major IT hubs. Economic prosperity changes lifestyles. As incomes rise, people eat more, buy vehicles and become less physically active.
That is why I often say the price we pay for affluence is diabetes and obesity.
Of course, prosperity itself is not the problem. If increasing incomes are accompanied by regular physical activity and healthier food choices, much of the risk can be reduced.
If you remove obesity from the equation, the differences between states narrow considerably. Even in people who do not appear obese, a relatively small amount of visceral fat can still be enough to trigger diabetes.
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Q. Annual health check-ups usually measure height, weight and BMI. Do you think waist circumference should become a routine measurement in every clinic and health camp?
A: One hundred percent. We have been saying for many years that BMI alone can give the wrong impression.
BMI is simply weight divided by height squared. But body weight includes both fat and muscle.
Take an Olympic boxer or a bodybuilder. Their BMI may be high because they have a lot of muscle, but they are extremely fit. Compare that with someone who has very little muscle but a large amount of visceral fat. Their BMI may look similar, but their metabolic risk is completely different.
Waist circumference is different because no muscle inside the abdomen can artificially increase the measurement.
In practical terms, only a few things can make the abdomen enlarge: fat, fluid or pregnancy. In an otherwise healthy adult, it is almost always fat.
That is why a simple measuring tape is enough.
If the waist circumference is 90 centimetres or more in men and 80 centimetres or more in women, abdominal obesity is present.
It is a much better test than BMI alone, and I believe we should stop relying only on BMI to assess metabolic health.
Q. Your study, along with NFHS data, shows abdominal obesity is much more common among women. Why are women disproportionately affected? Is it biology, lifestyle or both?
A: It is definitely a combination of biological, hormonal and social factors.
The first stage is puberty. Hormonal changes begin, and at the same time many girls become less physically active. Boys continue to play outdoor games, go to gyms and participate in sports. Girls are often told, “You have grown up now. Stay indoors.” That itself leads to weight gain.
The second stage is pregnancy. Families encourage women to eat much more during pregnancy, which is correct to an extent, but many women gain far more weight than the recommended eight to 12 kilograms.
After delivery, that weight rarely decreases.
The mother is busy looking after the baby. She sleeps less because the baby wakes up through the night. She has very little time to exercise or even look after her own health. Some women also develop postpartum depression, which further affects their lifestyle.
The third stage is menopause. As ovarian function declines and oestrogen levels fall, women naturally become more prone to weight gain, particularly around the abdomen.
Then there are social factors. Many women are told that household work is enough physical activity and that they do not need dedicated exercise. In many families, the earning member is given the healthiest food, while women eat whatever is left. Sleep is also compromised because women are often the first to wake up and the last to go to bed.
When you combine hormonal changes with social expectations and lower opportunities for physical activity, it becomes clear why abdominal obesity is more common among Indian women than among men.
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Q. GLP-1 drugs such as semaglutide and tirzepatide are now transforming obesity treatment. If someone has abdominal obesity but is not diabetic, should they consider these medicines?
A: Some of these drugs are approved for both diabetes and obesity.
Semaglutide is one example. It was originally developed for diabetes, but researchers soon realised that it had major benefits beyond blood sugar control. It reduces abdominal obesity and liver fat, and also lowers the risk of complications involving the heart and kidneys.
Tirzepatide is another such drug, and several newer medicines, including retatrutide and cagrisema, are likely to become available over the next few years. In fact, there are nearly 80 to 100 obesity medicines currently in different stages of development.
These drugs have completely changed the field of metabolic medicine.
However, they are not magic injections.
The first challenge is cost. Although generic versions have reduced prices, these medicines are still expensive for many Indians.
The second issue is duration.
People often ask me, “Can I take it for three months and then stop?”
The answer is no. These medicines work only as long as they are continued.
The moment you stop them, body weight starts increasing again. Liver fat returns, blood sugar rises, and many of the benefits gradually disappear.
People should think of them the way they think about medicines for hypertension or cholesterol. Those medicines are also taken for years.
Like any medicine, these drugs, too, have side effects.
Most patients experience mild nausea, vomiting, constipation or diarrhoea during the first few weeks, and these usually settle as the body adjusts.
Some people, however, cannot tolerate them because the symptoms become severe. There is also a small risk of pancreatitis. Rare cases of optic neuropathy affecting vision have also been reported internationally, although we have not seen many such cases in India so far.
Overall, I consider them excellent medicines.
Five years ago, we did not have treatments that could consistently reduce body weight and maintain that reduction. These medicines have changed that.
But they should always be prescribed under proper medical supervision.
I strongly discourage people from obtaining them through gym trainers, wellness centres or unqualified practitioners.
These are powerful medicines. Patients need proper evaluation, regular follow-up and monitoring before and during treatment.
Q. Your paper argues that individual behaviour alone cannot solve obesity because our food habits and urban environments shape our choices. If you could recommend three policy changes to governments, what would they be?
A: The priority is creating cities where physical activity becomes easy rather than difficult.
We need proper footpaths, safe pedestrian zones and parks where people actually want to walk. We should have free public gyms that are properly maintained. I have seen many countries where people can stop during a walk and use outdoor exercise equipment without paying anything.
In India, many parks have broken equipment or poorly maintained facilities. That discourages people from using them.
The second priority is healthy food.
We keep telling people to eat more fruits and vegetables, but many cannot afford them.
If an apple costs ₹80, how can an ordinary family eat one every day?
Government policies should make fruits, vegetables, pulses, legumes, nuts and seeds much more affordable. Just as India successfully expanded milk production through the White Revolution, we should think about making nutritious food available at prices every family can afford.
The third priority is starting early.
Schools should make physical activity compulsory rather than treating it as an optional period that students skip whenever examinations approach.
Children should be encouraged to play sports, spend time outdoors and bring healthy food to school instead of highly processed snacks.
Some schools have already started checking lunch boxes to ensure children are bringing healthier meals. These are small steps, but they help build lifelong habits.
Finally, I think obesity prevention has to involve every sector, not just doctors.
Urban planners, schools, governments, food systems and families all have a role to play.
This is not a problem that healthcare alone can solve. It requires a whole-of-society approach.
(Edited by Majnu Babu)
