South Asian Metabolic Health: What Changed?

OUR ANCESTORS ATE CARBS. SO WHY ARE WE STRUGGLING NOW?

For generations, rice, roti, dhal and other carbohydrate-rich foods have been part of South Asian diets. So when I talk about reducing refined carbohydrates or changing the balance of a traditional South Asian meal, I often hear the same perfectly reasonable question: “My grandparents ate rice three times a day. Why didn’t they all have diabetes?”

It’s a good question. If our families have eaten these foods for generations, why are South Asians now facing such extraordinary rates of type 2 diabetes, fatty liver and other metabolic diseases?

Perhaps we have been looking at the food in isolation. Our ancestors may have eaten many of the same foods, but the bodies eating them were living in a very different environment. Understanding that difference may be one of the missing pieces in the story of South Asian metabolic health.

What can our ancient ancestors teach us?

Let’s go back much further than our grandparents — more than 10,000 years.

Some hunter-gatherer populations living in South Asia were surprisingly tall and lived extraordinarily physically demanding lives. They walked long distances, hunted, gathered, carried, climbed and squatted. Their muscles were being used throughout the day, not for an hour at the gym a few times a week, but simply as part of being alive.

Yet archaeological research has uncovered something fascinating about their bodies. Researchers examining South Asian skeletons spanning approximately 11,000 years, and comparing them with more than 2,000 skeletons from populations around the world, found evidence suggesting that South Asians had relatively low lean mass for their height even in those earliest populations.

Why this pattern existed is still uncertain. One possibility researchers have proposed is long-term adaptation to hot climates, where a lighter, more linear body may have helped with heat loss. Ancient population variation may also have played a role.

But there is an important point here: these people were not weak. They were enormously active.

That distinction matters when we think about South Asian metabolic health today.

It’s not just how much muscle you have — it’s how much you use it

Muscle mass and muscle activity are not the same thing.

Imagine a lean, wiry person who spends hours every day walking, climbing, carrying, digging, squatting and gathering food. They may not have the large muscle mass of a modern strength athlete, but the muscle they do have is constantly being used.

Metabolically, that is incredibly important. Skeletal muscle is one of the major places our bodies dispose of glucose after we eat. Muscle contraction also helps increase glucose uptake, while regular physical activity improves insulin sensitivity.

So our ancient South Asian ancestors may have had relatively less lean mass for their height than some other populations, but they were continually using that muscle. That creates a very different metabolic environment from having relatively low muscle mass and then sitting at a desk for eight or ten hours a day.

And this may be one of the clues to understanding what has changed.

Then came another enormous change: agriculture

The transition from hunting and gathering to agriculture was one of the biggest shifts in human history. In parts of South Asia, agriculture began around 9,000 years ago and gradually spread over thousands of years.

The skeletal evidence suggests that something significant happened during this transition. Stature declined considerably. In one archaeological analysis, the estimated difference between Mesolithic hunter-gatherers and later South Asian populations was roughly 8.5 cm for men and 7.7 cm for women.

Agriculture brought obvious advantages, including a potentially more predictable food supply, but it also changed what people ate and how they lived. Populations could become more dependent on a smaller number of staple foods, while seasonal shortages, nutritional deficiencies and infectious diseases became increasingly important as communities became larger and more settled.

Our bodies and our environment continued to change over thousands of years. Then, extraordinarily recently in evolutionary terms, our environment changed again.

This time, it happened incredibly quickly.

South Asian metabolic health meets the modern world

Think about the lives of many of our grandparents compared with the lives we lead today.

Walking has become driving. Physical work has become desk work. Stairs have become lifts. Food that once had to be grown, gathered, prepared and cooked is now available at the supermarket, through a drive-through or delivered to our front door.

Our eating patterns have changed too. Traditional staple foods have often become more refined, meals have been joined by snacks, sugary drinks and convenience foods, and for many of us food is available from the moment we wake until the moment we go to bed. At the same time, our need to physically move has dramatically declined.

This is one of the great challenges for South Asian metabolic health: our environment has changed far faster than our biology.

Same bowl of rice. Very different body.

Imagine two people eating exactly the same bowl of rice.

The first has spent much of the day walking, lifting, carrying and doing physical work. Their muscles have been contracting repeatedly throughout the day. They eat their rice and then continue moving.

Now imagine someone eating the same bowl of rice after spending eight hours sitting at a computer. They drove to work, took the lift, sat through lunch, drove home and then ate dinner in front of the television. Perhaps there were snacks between meals as well.

The rice is the same.

The metabolic context is not.

This doesn’t make rice inherently “good” for one person and “bad” for another. It means we cannot consider the metabolic effects of food without also considering the body receiving that food and what that body has been doing.

This is why simply saying, “But my grandparents ate rice three times a day,” doesn’t tell us the whole story.

Why might South Asians have less room for error?

This modern environment matters even more because South Asians appear to have some particular metabolic vulnerabilities.

Compared with white Europeans at a similar BMI, South Asians tend, on average, to have lower skeletal muscle mass and greater susceptibility to abdominal and ectopic fat accumulation, including liver fat. We also tend to develop insulin resistance and type 2 diabetes at lower body weights. Differences in pancreatic beta-cell function may be another part of this complex picture.

In another article, I explain this using what I call the “metabolic wardrobe.” Read article HERE 

Imagine that your subcutaneous fat — the fat beneath your skin — is a wardrobe where the body can relatively safely store excess energy. Some people seem to have a huge walk-in wardrobe. They can store quite a lot before problems develop. Other people appear to have a much smaller cupboard.

When that safe storage space begins to run out, excess energy has to go somewhere. Fat may increasingly accumulate in places where we don’t want it, such as the liver and around the abdominal organs.

For many South Asians, therefore, we may have a particularly challenging combination: relatively less muscle available as a major site of glucose disposal, together with a tendency to develop harmful ectopic fat at a lower BMI. Modern life then adds less movement and a greater metabolic load.

The problem isn’t simply the rice. It’s the whole picture.

“But my grandparents ate like this and they were fine”

They may well have been. We shouldn’t dismiss that observation, but we should ask a few more questions.

How much did they walk? How much physical work was built naturally into their day? Did they sit for ten hours? How frequently did they snack? Did they drink sugary beverages every day? How much ultra-processed food did they eat? How refined were their staple foods, and was food continuously available from morning until night?

We should also be careful not to romanticise the past. Diabetes certainly existed, and people were not automatically metabolically healthy simply because they lived a traditional lifestyle. Many people were never diagnosed, and life expectancy and medical screening were very different.

But the environment surrounding traditional foods was profoundly different from the one in which we eat those foods today.

We kept the food — but lost much of the lifestyle

This, for me, is one of the most important messages about South Asian metabolic health.

Our traditional foods did not suddenly become poisonous. But in many families, we have retained the carbohydrate-rich parts of our traditional diet while losing much of the physical activity that once accompanied them.

At the same time, we have added foods our ancestors would barely recognise: sugary drinks, commercial snacks, highly refined foods, ultra-processed foods and sweets that were once occasional treats but can now be eaten every day. We also have an almost endless opportunity to eat while dramatically reducing the need to use our muscles.

That is the collision: ancient biology meeting traditional foods, modern abundance and very little movement.

And this is why I take such a firm stance on ultra-processed foods. These are not simply traditional foods in a modern packet. Many have been designed to be highly palatable, convenient and easy to consume, often making it remarkably easy to eat more without feeling adequately satisfied.

When we already live in an environment of abundant food and minimal physical effort, I don’t believe ultra-processed foods need to form part of our everyday diet.

Do we have to give up our cultural foods?

Absolutely not.

I think this is where conversations about South Asian nutrition can go badly wrong. The answer is not to tell a Sri Lankan family that they can never eat rice again, or an Indian family that they must abandon roti, dhal and the foods that connect them to family, celebration and culture.

We need to change the balance, not abandon our culture.

I encourage people to start with protein and build the meal around a meaningful protein source such as eggs, fish, chicken, meat, paneer, tofu or Greek yoghurt. Add plenty of above-ground, non-starchy vegetables, and then consider how much rice, roti or other starch suits your individual metabolic health and activity level.

And then there is muscle. We need to build it, preserve it and, importantly, use it. Walk, lift, move after meals and break up prolonged sitting. We don’t need to recreate a hunter-gatherer lifestyle or spend six hours searching for dinner! But we can recognise what has disappeared from modern life and deliberately put some of it back.

Ancient bodies. Modern mismatch.

Perhaps our grandparents could eat foods that many of us now struggle with because we inherited the food but not the environment in which it was traditionally eaten.

And perhaps our much older ancestors give us an even more interesting clue. South Asians may have had relatively low lean mass for their height for thousands of years, yet those ancient populations lived lives filled with movement.

Today, some of that biological vulnerability may be meeting an environment our ancestors could never have imagined: abundant food, frequent eating, refined carbohydrates, ultra-processed foods and remarkably little requirement to use our muscles.

So perhaps the most useful question is no longer:

“How did my grandparents get away with eating rice?”

Maybe we should ask:

“What was their body doing all day that mine no longer has to do?”

Because the answer to the South Asian diabetes epidemic is unlikely to be found in one food. It lies in the relationship between the bodies we inherited and the environment we have created.

And unlike our ancestry, that environment is something we can change.