metaboliq
The report from the pre-employment medical says fasting insulin 19, flagged, with "suggestive of insulin resistance" typed underneath. He's 34, an engineer in Pune, hardly touches sweets and wears the same size jeans he wore in college. So what happened? Usually several ordinary things, adding up quietly for years.
Usually it's fat stored deep in the belly and in the liver, combined with too little muscle, long hours of sitting and short or broken sleep. Genes and family history decide how easily that tips into insulin resistance, and South Asians tend to get there at a lower weight than Europeans. PCOS, some hormone conditions and treatments such as steroids can add to it, and apart from genes and birth weight, nearly all of it can be changed.
Is insulin resistance caused by eating sugar?
Sugar is usually the first thing people cut, and it does play a part. A sweet drink or a big plate of white rice pushes insulin up for a few hours, and food like that is easy to overeat. Someone taking two spoons in each of four cups of chai a day should cut back. The mistake is treating that as the whole plan. A forty-year-old man with a 38-inch waist, a desk job and six hours of sleep can stop sugar completely and still see his fasting insulin go up on every yearly report.
Insulin resistance is a change in the cells, and sugar is one of several things pushing on them. Muscle, liver and fat tissue each respond less to insulin, by different amounts. The pancreas covers for them by making more, so blood sugar can hold steady for years while insulin rises. Fat stored around the organs, too little muscle, long hours in a chair and short sleep do most of the damage. Genes decide how fast it happens to a given person, which is why one brother can eat mithai every evening and stay fine while the other cannot.
So if you gave up sugar six months ago and the report hasn't budged, you haven't failed. You've dealt with the smallest of the causes. The rest of this page goes through the bigger ones in order.
Sources: [1]
Why is belly fat the biggest driver?
Two colleagues who both weigh 72 kg can get very different reports from the same office health camp. Where they carry the fat is usually the reason. Fat under the skin of the hips and thighs is a fairly safe store. Fat packed deep inside the abdomen, around the intestines and organs, leaks fatty acids and signalling molecules that get in the way of insulin. The liver next to it takes the worst of it. A joint position statement from cardiology and endocrinology experts put most of the metabolic risk people blame on weight down to this deep visceral fat, plus fat stored inside organs.
Look in the mirror side-on. If the waist has grown faster than everything else, with a firm, round belly on slim arms and legs, that's the pattern. Trousers go up two sizes while the shirt size stays put. Plenty of Indian men in their thirties and forties look like this and have never once thought of themselves as overweight. A tape measure around the navel tells them more than the bathroom scale.
Sources: [2]
What does fat in the liver have to do with it?
A liver that has filled up with fat stops responding properly to insulin and keeps releasing glucose into the blood after a meal, when it should have stopped. The pancreas then has to make even more insulin to bring sugar down, which pushes the whole cycle further along. So fatty liver ends up as both a cause of insulin resistance and a result of it.
Research on obesity and fatty liver has found that liver fat tracks closely with insulin resistance, and that the liver enzymes on a routine report are a poor way to spot it. It often goes like this. SGOT and SGPT come back within range on the annual package and everyone relaxes. A few years later an ultrasound done for a kidney stone mentions a fatty liver in passing. It's common in India, often in people who drink little or no alcohol, so being teetotal doesn't rule it out. If your waist is growing and your sugars are drifting, it's fair to ask your doctor whether an ultrasound is worth doing.
Sources: [3]
Why do Indians develop it at a lower weight?
Researchers comparing healthy Asian Indian and Caucasian men of similar body size found the Indian men markedly more insulin resistant, with more fat in the abdomen at the same BMI.
It may start in the womb. The Pune Maternal Nutrition Study found Indian newborns were smaller than white Caucasian babies yet kept their body fat, the "thin-fat" baby. The Y-Y paradox paper photographed the adult version: two men with the same BMI, one Indian and one European, carrying very different amounts of fat.
So a fitness app telling a Lucknow man with a BMI of 23 that he's fine may be wrong for him. That's especially true if his waist has grown since the wedding and his mother has diabetes. A tape measure and a fasting blood test are better guides.
How does muscle protect against it?
Skeletal muscle is where most of the glucose from a meal ends up. Ralph DeFronzo, who spent much of his career measuring this, argues that insulin resistance in muscle is the primary defect in type 2 diabetes. When muscle stops taking up sugar well, there's nowhere else big enough to put it, and the pancreas has to work harder to push it in. A large US national survey came at the same question from the other side and found that adults with more muscle for their body size had less insulin resistance and lower odds of prediabetes. The muscle in your thighs and back is part of how your body copes with a plate of rice.
Take a father who was fairly active until fifty, then retired, sat more, and spent a month in bed after a bad bout of illness. He comes out of it with thinner arms and higher sugars, and his weight has hardly changed. Muscle goes with age, illness and crash diets, and the scale can barely move while fat takes its place. If someone at home is losing weight on a very low-calorie diet, notice whether they're also getting weaker on the stairs or struggling with the gas cylinder.
A word on who's writing this, since it's our site. Metaboliq is a doctor-led programme, and its aim is "Lose up to 20% of your body weight — and keep your muscle". Results vary; your doctor decides what is right for you. That second half is there because of everything in this section. It starts with a ₹1,699 blood test at home, read by a doctor, so the plan is built around whichever causes show up in your own results.
How much do sitting and inactivity matter?
Working muscle can pull glucose out of the blood by routes that don't fully depend on insulin, and a single session of exercise improves insulin sensitivity for a day or more afterwards. A review of the research on physical activity and insulin sensitivity sets these effects out in detail. Because one session wears off within a day or two, a brisk walk on most days does more for your insulin than a long trek once a month.
Take the daily movement away and that benefit disappears just as fast. A typical Bengaluru or Gurugram workday runs something like this: an hour in a cab, nine hours at a desk with lunch delivered to it, another hour home, then dinner and the sofa. A generation ago the same job might have meant a bus ride, three flights of stairs and a walk to the market in the evening. Urban Indians have swapped stairs and bicycles for lifts, scooters and screens, and that drop in everyday movement matters as much as any change in what we eat.
Sources: [9]
Can poor sleep cause insulin resistance?
In a controlled study, healthy young men had their sleep cut to about five hours a night for a week, with their food kept the same. By the end of that week they were measurably less sensitive to insulin, from the lost sleep alone.
Five hours is an ordinary night for a lot of people. It might be a late call with a US team, scrolling in bed until 1am, a newborn, or a spouse whose snoring and pauses in breathing keep the room awake. That last one may be untreated sleep apnoea, which is worth getting checked. If your eating and activity look reasonable and the reports keep drifting, add up how many hours you actually slept last week, as opposed to how long you were lying in bed.
Sources: [10]
Which conditions and family factors add to it?
Ask around at any family function and you'll usually find an uncle with diabetes, a mother who checks her sugar every morning, a cousin who has been told to watch the sweets. A parent or sibling with type 2 diabetes raises your own risk. In each of them, insulin resistance was probably climbing for years while the pancreas made extra insulin to hold sugar steady, and the diagnosis came when it fell behind. That history doesn't make diabetes inevitable for you, but it's a reason to get tested earlier and to take a slowly rising fasting sugar seriously.
Polycystic ovary syndrome is closely tied to it, and women with PCOS show reduced insulin sensitivity whatever their weight, so a slim 24-year-old with irregular periods should still be checked. Diet adds pressure too. A Chennai study found that people eating more refined grains, such as polished white rice and maida, had higher odds of metabolic syndrome. Some hormone disorders and long-term treatments such as steroids can also make insulin work less well, so tell your doctor about any medicine you've been taking for months.
Which popular explanations don't hold up?
Every summer someone in the family group forwards a message saying mangoes cause diabetes. Whole fruit comes with fibre and water, and for most people it isn't what drives insulin resistance. The glass of packaged juice that often replaces it is worse, because the same sugar arrives fast with nothing to slow it down.
Ghee gets similar treatment. What adds up is the total fat and calories over a day. A plate of pakoras or bhujia with evening chai most days counts for far more than the spoon of ghee on a roti. Swapping that ghee for refined sunflower oil won't change much on its own.
Then there's the aunt at every family lunch with a rule about dinner before 8pm, never skipping breakfast or never drinking cold water with food. None of those has evidence anywhere near what stands behind belly fat, muscle, movement and sleep. If you can manage only a couple of changes this year, start with a daily walk and an earlier bedtime and let the clock-watching go.