Weight & Metabolic · Weight science

Insulin Resistance: The Quiet Years Before Diabetes, and How to Take Them Back

Written by TSMC/FMR/36195 · Published: September 3rd, 2026 · ~13 min read · 20 references
A man in a dark shirt leans back in his office chair with his eyes closed after lunch, an empty plate and a coffee cup on the table in front of him.
The heavy hour after a big meal is the one insulin resistance quietly rewrites first.

ICMR-INDIAB estimated that in 2021, 101 million people in India had diabetes and another 136 million had prediabetes.1 For much of type 2 diabetes, the metabolic changes begin years earlier, with some combination of insulin resistance and progressive beta-cell dysfunction. Insulin resistance is also closely tied to visceral fat, fatty liver and PCOS, particularly in South Asian bodies. And during the early, compensated stage, fasting glucose and HbA1c can still look normal, because the pancreas is producing extra insulin to keep glucose controlled. That is the useful window this page is about: a metabolic state that often improves substantially when its drivers are treated.

What is insulin resistance, in simple terms? Copy link

Insulin is the hormone that moves glucose out of your blood and into your cells, muscle above all, where it becomes energy. Insulin resistance means those cells have started responding sluggishly to the signal. The glucose still has to go somewhere, so the pancreas does the only thing it can: it shouts louder, releasing more insulin to force the same doors open.2

And for a time, that compensation can work. Your fasting glucose and HbA1c may remain normal because the pancreas is producing more insulin to maintain glucose control. What has changed is not necessarily the glucose number but how hard the system is working to hold it there. That compensation is the whole story of insulin resistance, and it is why the condition hides so well. The body is not failing yet. It is succeeding, expensively.

Why does it stay silent for years? Copy link

Because routine glucose tests measure glycaemia, not insulin sensitivity. A fasting glucose or HbA1c reports the level of sugar in your blood; it says nothing about how much insulin your pancreas is spending to hold it there. So the sequence below can run for years while every report card you file away reads “normal.”

The hidden years: insulin rises for years to keep blood sugar normal, then plateaus and later declines as sugar climbs into diabetes A chart across four stages: healthy, early insulin resistance, prediabetes, type 2 diabetes. A green blood sugar line stays flat through the first two stages, drifts up in prediabetes and climbs in diabetes. A deep-red insulin line climbs through the first three stages, doing the hidden work of keeping sugar normal, then plateaus; it can remain high early in type 2 diabetes and declines later as beta-cell function deteriorates. A standard sugar test only turns abnormal in the last two stages. The hidden years blood sugar insulin Healthy Early insulinresistance Prediabetes Type 2 diabetes a routine sugar test still looks normal here tests turn abnormal only from here Schematic, not to scale. Insulin often stays high early in type 2 diabetes and falls later.
For years, sugar looks fine because insulin is working overtime to keep it that way. Routine tests only turn abnormal in the last two stages.

In people who progress, the insulin-making beta cells can no longer compensate for the degree of resistance. Glucose then begins to rise into the prediabetes range and, in some people, on into type 2 diabetes.2 That does not necessarily mean insulin levels suddenly become low: they can stay high early in type 2 diabetes and fall later as the beta cells wear down.

The 2026 ADA thresholds are worth having in one place.3

MeasurePrediabetesDiabetes
HbA1c5.7–6.4%≥ 6.5%
Fasting plasma glucose100–125 mg/dL≥ 126 mg/dL
2-hour glucose, 75-g OGTT140–199 mg/dL≥ 200 mg/dL

One rule sits alongside the table. In someone without unequivocal symptoms, an abnormal result should be confirmed before the diagnosis is applied.3 The point of this page is the stretch before any of those numbers move, because that is where the most improvable version of the problem lives, and it is exactly the stretch your once-a-year sugar test was never designed to see.

Which conditions travel with insulin resistance? Copy link

It rarely appears under its own name. It shows up wearing other diagnoses, and the family resemblance is worth learning:

  • Type 2 diabetes and prediabetes, the direct endpoint when compensation finally fails.
  • Metabolic fatty liver, which is strongly associated with insulin resistance and visceral fat. ALT/SGPT may be elevated, but it can also stay normal, so liver enzymes alone neither diagnose nor exclude it; the liver function test guide explains why.
  • PCOS, in which insulin resistance is an important feature for many women and can amplify androgen excess and metabolic risk, one reason irregular cycles, acne and facial hair so often travel with a rising waist.
  • Central weight gain, in a loop that runs both ways: visceral and ectopic fat impair insulin sensitivity, while the metabolic and hormonal changes that follow can make weight regulation harder. More on that loop in the visceral fat guide.
  • Metabolic syndrome, the familiar cluster of large waist, rising blood pressure, high triglycerides, low HDL and creeping sugar, with insulin resistance as the thread through all five.4

These conditions share several biological drivers. That is why improving insulin sensitivity, visceral fat, activity and overall metabolic health can move several markers in the right direction together, and it is also why each condition still deserves its own diagnosis and its own treatment.

What are the symptoms of insulin resistance? Copy link

Mostly, there are none, and that is the straight answer. But the condition does leave clues, on your body and in blood reports you may already have sitting in a drawer.

Clues to insulin resistance: on the body, and in routine blood tests Two panels. On the body: a waist of 90 centimetres or more in men, 80 in women; dark velvety patches on the neck or underarms; skin tags; in women, irregular cycles or PCOS features. In routine checks: triglycerides high with HDL low; HbA1c creeping through 5.7 to 6.4 percent; ALT mildly raised with a fatty liver. No single clue is diagnostic; several together mean it is time to test properly. The clues it leaves ON THE BODY · Waist ≥ 90 cm (men) / 80 cm (women) · Dark, velvety neck or underarm patches (acanthosis nigricans) · Skin tags around neck or armpits · In women: irregular cycles, acne, excess facial hair (PCOS features) IN ROUTINE CHECKS · Triglycerides high, HDL low · HbA1c creeping through 5.7–6.4% · ALT/SGPT mildly raised, or a fatty liver on ultrasound · Blood pressure edging up No single clue is diagnostic. Several together are a reason to test properly, never to panic.
None of these is diagnostic alone. Two or three together are a reason to test properly.

One clue deserves its own paragraph, because in India it is routinely misread. Acanthosis nigricans, the medical name for a dark, velvety thickening of skin most often seen around the neck and the major folds, is a recognised clinical marker associated with high insulin, and Indian expert guidance treats it as a prompt to screen.5

Families scrub at it, blame the sun, blame hygiene. It does not wash off, because, as you would expect, it was never dirt. It is a reason to test, and in a young person it is a particularly valuable early flag. Skin tags in the same areas tell a similar story. And in women, the combination of irregular periods, stubborn acne and excess facial hair points toward PCOS, a clue to the overlapping insulin-resistance and androgen biology seen in many women with the condition.

Why do Indian bodies develop insulin resistance early? Copy link

Because of body composition. On average, South Asian populations carry more body fat and less lean mass at a given BMI, with a greater tendency to store fat centrally and inside organs such as the liver, so-called ectopic fat, than many European-origin populations. This is a population-level tendency, not a rule for every individual. The pattern has a name in the literature, thin-fat, and it has consequences.6

Both halves matter here. Visceral and liver fat actively promote resistance, and muscle is the main destination for the glucose insulin disposes of, so starting with less muscle means starting with less capacity.7 The result is insulin resistance that begins earlier in life, at lower body weights, and often behind a completely normal-looking frame. The classic Y-Y comparison that helped popularise the pattern showed two physicians with the identical BMI of 22.3: the Indian physician’s body fat measured 21.2 per cent, while the European physician’s came to 9.1.8

The national data shows where that leads. ICMR-INDIAB-23 found that 43.3 per cent of adults met its definition of “metabolically obese non-obese.” That means a BMI below 25 together with at least two abnormalities from among a raised waist, elevated blood pressure or glucose, high triglycerides, or low HDL.9

That figure comes from the blood-tested subsample, and the detail worth sitting with is the age one: more than a third of adults in their twenties were already in that group. Read it as a warning about relying on BMI alone, never as a direct measurement of insulin resistance. And one more calibration for Indian readers: a BMI of 23 to 24.9 already sits in the increased-risk range on Indian cut-offs, so “below 25” should not be read as metabolically reassuring.10 If your weight has been reassuring you, let your blood work take over that job; it is far better qualified.

How is insulin resistance tested? Copy link

Here you deserve the answer a doctor would give a colleague. There is no single routine test that certifies insulin resistance, and the research-grade methods are impractical outside studies. What exists is a sensible, inexpensive workup that reads the condition from its footprints:

CheckWhat it tells you
Waist measurementA simple proxy for central fat and metabolic risk; risk begins at 90 cm for men, 80 for women10
HbA1c + fasting glucoseWhere you sit on the staircase above; the prediabetes band spans 5.7 to 6.43
Lipid profileRaised triglycerides paired with a low HDL is the classic resistance pattern
Liver enzymes ± ultrasoundA mildly raised ALT/SGPT with central weight raises suspicion of fatty liver
Blood pressureCompletes the metabolic-syndrome picture

What about measuring insulin itself? Fasting insulin and the HOMA-IR score calculated from it are useful research tools, and specialists occasionally order them.11 They are not standard screening tests, and for an unglamorous reason: current laboratory guidance still calls for insulin assays to be standardised so that measures of insulin sensitivity are comparable, which is a large part of why HOMA-IR has no universally accepted cut-off.12

In PCOS specifically, current international guidance recommends against routine insulin assays and prefers a 75-g OGTT when glycaemic status needs assessing.13 And a practical honesty about the workup above: it is simple, but it is not one blood test. Waist and blood pressure are measured clinically, glucose and lipids come from a blood draw, and liver imaging is added only when the history or results justify it.

How do you reverse insulin resistance? Copy link

First, one word of calibration: “reverse” is useful shorthand, but the clinical target is to improve insulin sensitivity and shrink the metabolic risks that travel with it. Sensitivity can improve substantially; whether it returns fully to an earlier state varies from person to person.

The strongest outcome evidence comes from diabetes-prevention trials, and it is unusually encouraging. In the US Diabetes Prevention Program, intensive lifestyle intervention reduced progression to type 2 diabetes by 58 per cent, beating the medication arm.14 And in India’s IDPP-1, run in Chennai with the very phenotype this page describes, lifestyle intervention reduced progression by 28.5 per cent over a median of about two and a half years in people with impaired glucose tolerance, the OGTT version of prediabetes.15

For adults with overweight or obesity who are at high risk of type 2 diabetes, the 2026 ADA recommends a diabetes-prevention programme targeting at least a 5 to 7 per cent weight reduction and at least 150 minutes a week of moderate-intensity activity.16 Sensitivity is not a fixed trait. It is a state, and states change.

Four levers that improve insulin sensitivity: strength training, modest weight loss, movement after meals, and sleep Four panels. Train the sink: muscle clears most of the glucose insulin disposes of, so strength work twice a week builds capacity. Shrink the deep fat: even five to ten percent weight loss improves sensitivity. Move after meals: short walks after eating blunt the glucose rise. Protect sleep: even a few short nights measurably reduces insulin sensitivity. Four levers, all of them yours Train the sink Muscle clears most of the glucose insulin disposes of. Strength work twice a week builds capacity. Shrink the deep fat Even a 5–10% weight loss meaningfully improves how cells respond to insulin. Move after meals Short walks after eating blunt the post-meal glucose rise, when it matters most. Protect the sleep Regular, adequate sleep supports glucose regulation and metabolic health. These changes work together; sustained improvement can raise insulin sensitivity and lower future risk.
The levers work together, and every one of them is available this week.

Train the sink. Skeletal muscle clears the large majority of the glucose insulin disposes of, which makes it the closest thing the body has to a sugar sink, and makes resistance training a metabolic intervention, well beyond a cosmetic one.7 Twice a week is a serious start, and it is particularly relevant in South Asian populations, which on average carry less lean mass at a given BMI. Feed the work with protein; the protein guide has targets and the vegetarian arithmetic.

Shrink the deep fat, if there is deep fat to shrink. If you carry overweight or excess central fat, a weight loss in the 5 to 10 per cent range can meaningfully improve insulin sensitivity and metabolic risk, and the improvement often arrives well before any dramatic change in the mirror. If your weight already sits in a healthy or low range, further weight loss is not automatically the goal; activity, muscle, diet quality and the underlying diagnosis matter more. The tool is a moderate calorie deficit, and the belly fat guide covers how to track progress at the waist.

Move after meals. The hours after eating are when glucose and insulin peak, and they are the cheapest hours to fix. Short post-meal walks are a practical, low-risk habit: in one small controlled study of ten older adults at risk of impaired glucose tolerance, three 15-minute walks timed after meals improved 24-hour blood sugar control, with a particularly useful effect after dinner.17 Ten people is a small study, and, in practice, a walk after your largest meal costs nothing to try.

Protect the sleep. In a classic experimental study, restricting healthy young men to four hours in bed for six nights measurably impaired their glucose handling, before any weight changed.18 Chronic short sleep keeps that experiment running nightly. That does not make any particular number of hours a standalone treatment; it does make adequate, regular sleep part of the plan, never a luxury outside it.

Food deserves one plain paragraph, and national data explains the Indian part of the problem. ICMR-INDIAB’s dietary study, covering 18,090 adults, found carbohydrate supplying 62.3 per cent of daily energy, including 28.5 per cent from refined cereals, while protein supplied just 12 per cent.19 The practical response is not to ban carbohydrate. Trim oversized portions of refined cereals and added sugar, anchor meals with protein, keep dals, vegetables and intact grains, and let sweet drinks go first. No food is banned; the plate is rebalanced. Readers who want the full arithmetic will find it in the calorie-deficit and protein guides above.

When is medicine part of the answer? Copy link

According to overall risk, and never simply because one number crossed into prediabetes. Lifestyle work stays foundational. Metformin, the oldest and best-known insulin sensitiser, can be considered for diabetes prevention in selected higher-risk adults, and PCOS, established diabetes and obesity each carry their own treatment indications.16 And for people who meet the prescribing criteria on weight, the GLP-1 medicines produce substantial weight loss in trials,20 and insulin sensitivity generally improves as weight falls. In India these are prescription products with product-specific licences; the GLP-1 guide and medical weight loss pages lay out the options.

One reframe helps here: needing medical help with insulin resistance is not a lifestyle failure. It is a treatable point on a staircase, and the whole purpose of catching it early is to have more options, used sooner, with more effect.

Insulin resistance, question by question Copy link

What is insulin resistance in simple words?

Your cells respond less effectively to insulin, the hormone that moves sugar from blood into cells, so the pancreas often compensates by producing more of it. During this compensated phase, blood glucose can remain normal. Insulin resistance raises the risk of prediabetes and type 2 diabetes, but progression is not inevitable.

What are the warning signs of insulin resistance?

Usually none you can feel. The visible clues are a waist at or beyond 90 cm in men or 80 in women, dark velvety patches on the neck or underarms, skin tags, and PCOS features in women. On routine bloods, high triglycerides with low HDL, an HbA1c inside the prediabetes band, or a mildly raised SGPT are the common footprints.

Can a thin person have insulin resistance?

Yes. South Asians can develop insulin resistance and related metabolic abnormalities at lower BMIs than people often expect. ICMR-INDIAB-23 found that 43.3 per cent of adults met its “metabolically obese non-obese” definition, a BMI below 25 with at least two specified metabolic abnormalities. That survey counted the abnormalities themselves; insulin resistance was never measured directly.

Does insulin resistance mean I will need insulin injections?

No. Insulin resistance means your tissues respond less effectively to your own insulin; it does not mean you need insulin injections. Insulin is essential in type 1 diabetes and may also be used at different stages of type 2, including at diagnosis when blood sugar is severely high. Most people found to have insulin resistance alone are managed by treating the underlying metabolic risks, not by giving insulin.

What is the difference between insulin resistance and prediabetes?

They overlap, but they are not the same thing. Insulin resistance describes a reduced biological response to insulin and can exist while glucose remains completely normal. Prediabetes is defined by glucose or HbA1c values above normal but below the diabetes cut-offs, and it often reflects insulin resistance combined with the insulin-making beta cells starting to fall behind.

Is there a test for insulin resistance?

Not a single routine one. Doctors read it from a set of footprints: waist measurement, HbA1c and fasting glucose, a lipid profile, liver enzymes and blood pressure. Fasting insulin and the HOMA-IR calculation are occasionally used in specialist settings, but insulin assays are poorly harmonised between labs, and in PCOS current guidance prefers a 75-g OGTT over insulin testing.

How do I reduce insulin resistance quickly?

Nothing works overnight, and the levers act faster than people expect. Strength training builds the muscle that clears glucose. If you carry excess weight, shedding 5–10 per cent of it improves sensitivity meaningfully. Moving after meals helps too: one small controlled study in ten older adults found benefit from three 15-minute post-meal walks, particularly after dinner, so the practical message is to walk after meals rather than to treat one 15-minute slot as a magic dose. Regular, adequate sleep supports glucose regulation and metabolic health. Prevention trials in India and abroad show these steps cut progression to diabetes substantially.

Does insulin resistance cause weight gain, or does weight gain cause it?

The relationship runs in both directions, but not equally simply. Excess visceral and ectopic fat is a well-established driver of insulin resistance. Insulin resistance often coexists with higher insulin levels and can make metabolic regulation harder, but it is too simple to say it automatically causes weight gain. In practice, improving body composition, activity and diet is what breaks the cycle.

Which foods should I avoid with insulin resistance?

Think pattern, never a banned list. The Indian plate’s weak points for this condition are sugary drinks, refined cereals eaten in large repeat portions, and deep-fried snacks; its strengths are dals, vegetables, curd, eggs, fish and intact grains. Rebalancing toward protein and fibre while trimming refined carbohydrate serves insulin sensitivity, provided the overall day still suits your calorie needs.

References Copy link

  1. Anjana RM, Unnikrishnan R, Deepa M, et al. Metabolic non-communicable disease health report of India: the ICMR-INDIAB national cross-sectional study (ICMR-INDIAB-17). Lancet Diabetes Endocrinol. 2023;11(7):474-489. doi:10.1016/S2213-8587(23)00119-5
  2. Petersen MC, Shulman GI. Mechanisms of insulin action and insulin resistance. Physiol Rev. 2018;98(4):2133-2223. doi:10.1152/physrev.00063.2017
  3. American Diabetes Association Professional Practice Committee. Diagnosis and classification of diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1). doi:10.2337/dc26-S002
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  11. Matthews DR, Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412-419. doi:10.1007/BF00280883
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This article is for information and education and does not replace a consultation with a doctor who knows your history. Diagnostic thresholds cited are current guideline values and may be revised; testing decisions, medication choices and PCOS evaluation are individual clinical judgements. Consultations on Sapiens are provided by registered medical practitioners under the Telemedicine Practice Guidelines 2020, and prescription treatments are dispensed only against a valid prescription. Regulatory status of medicines in India is stated as of the publication date. To report an error, use this form or write to editorial@joinsapiens.in.