How blood sugar quietly spirals: the insulin resistance story

Most people find out they have diabetes not because they felt sick, but at a routine check-up. That delay matters — the body was quietly working around the problem for years before the number showed up on a report.

The underlying story is almost always insulin resistance. The pancreas makes insulin, a hormone that acts like a key to let glucose into your cells for energy. When cells stop responding well to that key — typically from excess weight around the middle, too little movement and too many refined carbohydrates — the pancreas compensates by making more. Blood sugar can stay normal for years while this overwork continues. Then the pancreas tires. The glucose climbs. Only then does the number get a name.

• Pre-diabetes is reversiblecaught in this window, blood sugar can return to normal entirely through lifestyle changes.
• Two tests matterHbA1c for the three-month average, fasting plasma glucose for the single-day snapshot.
• India's risk profile is differentSouth Asians develop diabetes at lower body weights and younger ages than Western populations — our metabolic threshold sits lower.

These five terms appear on every diabetes report. Once they are clear, the numbers stop being alarming and start being useful.

Glucose

The main fuel your body runs on. It comes from food — especially carbohydrates — and travels in the blood until insulin helps it enter cells. Whatever is not absorbed stays in the blood; that excess, over years, is what damages nerves, kidneys and blood vessels.

Insulin

The hormone made by beta cells in the pancreas. Its job is to signal cells to open their gates and absorb glucose. Think of it as a key that every cell must recognise. When cells stop recognising it well, more keys are needed for the same job — that state is called insulin resistance.

Insulin resistance

A condition where cells need far more insulin than normal to move the same amount of glucose. The pancreas compensates by producing more. Blood sugar may look normal for years. The real damage in this phase comes from chronically high insulin itself, and from the gradual exhaustion of the pancreas.

HbA1c

Glycated haemoglobin — a blood test that shows average blood sugar over the past two to three months, not just the day of the test. It captures the slow drift that a single fasting measurement can miss.

Fasting plasma glucose

Blood sugar measured after at least 8 hours of not eating. The baseline when insulin has had time to work. Interpret it alongside HbA1c, not instead of it.

Insulin resistance does not arrive one morning. It builds over years, driven by four things that reinforce each other.

Excess abdominal fat. Fat cells packed around the liver and pancreas — visceral fat, not the subcutaneous kind you can pinch — release inflammatory signals and free fatty acids that interfere directly with insulin's signalling pathway in muscle and liver cells. This is why waist circumference matters more than total body weight, and why India's high waist-to-hip ratios at lower BMI values are so significant.

Physical inactivity. Muscle is the body's biggest glucose consumer. When muscles are regularly contracted through movement, they can take in glucose without needing insulin at all — a protein called GLUT4 opens independently during exercise. Inactivity closes this shortcut. The entire load falls on the pancreas.

Dietary pattern. High glycaemic foods — white rice, maida, sugar-sweetened drinks — spike blood glucose sharply. The pancreas releases a surge of insulin each time. When these surges happen repeatedly through the day, cells begin tuning them out, like ignoring a car alarm that never stops.

A fatty liver. Fat deposited in the liver causes it to release glucose into the blood even when not needed — an override that adds to the background burden and worsens overnight fasting glucose in particular.

Long lists of statistics numb more than they inform. Three numbers, placed carefully, are enough.

101 million Indians live with diabetes (ICMR-INDIAB 2023). That is one in eleven adults. Another 136 million sit in the pre-diabetes band — glucose elevated, not yet diabetic, and largely unaware. Together that is nearly one in three adults affected by blood sugar that is either too high or heading there.

A decade younger. India's average age at type-2 diabetes onset is roughly a decade earlier than in Western countries — many diagnoses happen in the forties rather than the fifties or sixties. South Asian genetics, high-carbohydrate diets built around white rice and maida, and widespread sedentary work patterns explain most of this gap.

58% reduction in conversion risk. The Diabetes Prevention Programme, replicated across multiple countries, found that pre-diabetics who lost 5–7% of their body weight and walked 150 minutes per week reduced their risk of converting to type-2 diabetes by about 58% over three years. No medication in the pre-diabetes window comes close to that number.

Note on costs: HbA1c at a diagnostic lab typically costs ₹300–800; fasting plasma glucose, ₹60–150. Both numbers together, for an hour's effort, are the cheapest investment in metabolic clarity you will make this year.

Myth 1 — Just cut sweets and you are fine.

Sugar is one trigger, not the only one. White rice, maida bread, large portions of potato and any sugar-sweetened drink all spike blood glucose just as sharply as sweets. Cutting mithai while eating three plates of rice at every meal misses the point entirely.

Myth 2 — Thin people do not get diabetes.

They do — and in India this is especially common. South Asians can carry high visceral fat at a normal-looking body weight. A slim person with a soft, wide belly and a sedentary life can be deeply insulin resistant. The visible body does not tell the full metabolic story.

Myth 3 — Once on medication, always on medication.

For people who catch pre-diabetes or early type-2 and make sustained, meaningful lifestyle changes, some do come off medication entirely. It depends on how much beta-cell function remains and how committed the changes are. This is a real possibility — not a guarantee, but real.

Myth 4 — Family history means you will definitely get it.

Family history raises the risk, not the certainty. Many people with a strong family history never develop diabetes. Lifestyle is where you have leverage, regardless of the genes.

Myth 5 — Fruit is sugar and must be avoided.

Whole fruit, eaten in reasonable amounts, is not the problem. The fibre slows absorption and blunts the glucose spike. Fruit juice — where the fibre is removed — behaves very differently and is worth limiting.

Pre-diabetes is not a warning — it is a window to act. The evidence on what moves the number is clear.

Use this as a reference the next time a report comes back.

HbA1c (no fasting needed, ₹300–800)

• Below 5.7% → Normal
• 5.7–6.4% → Pre-diabetes (act now, this is the reversible window)
• 6.5% or above → Diabetes (needs confirmation on a second test)

Fasting plasma glucose (8+ hours without food, ₹60–150)

• Below 100 mg/dL → Normal
• 100–125 mg/dL → Impaired fasting glucose (a form of pre-diabetes)
• 126 mg/dL or above → Diabetes (needs confirmation)

Post-prandial glucose / PPBS (2 hours after a standard meal, ₹80–200)

• Below 140 mg/dL → Normal
• 140–199 mg/dL → Impaired glucose tolerance (a pre-diabetes variant)
• 200 mg/dL or above → Diabetic range

Why this matters: some people show normal fasting sugar but spike sharply after meals — PPBS catches what the other two miss.

Waist circumference (free — measure at the navel)

• Men: ≥90 cm at navel → elevated abdominal fat risk
• Women: ≥80 cm at navel → elevated abdominal fat risk

These are Indian-specific cut-offs from ICMR, lower than global WHO thresholds, because South Asians carry metabolically active visceral fat at lower body weights.

All test costs are approximate and vary by city, lab and time. Your doctor interprets results in the context of symptoms and full medical history — these numbers are orientation, not diagnosis.

The harder lesson here is not about glucose readings or which tests to order. It is about what India has done with several generations of food and lifestyle transition compressed into a few decades.

The traditional Indian diet — dal-chawal, roti-sabzi, measured ghee, seasonal vegetables, moderate portions — was broadly slow-digesting and balanced for the physical work most people were doing. The shift toward refined grains, less pulse consumption, more sedentary urban jobs and less daily walking has happened within one or two generations. The pancreas has not evolved to keep up. The epidemic of diabetes and pre-diabetes is the consequence — visible, measurable and still growing.

The broader implication matters at two levels. At the individual level, the pre-diabetes window is real, finite and interruptible. Acting in that window — a modest weight reduction, 150 minutes of walking a week, a partial shift away from white rice — genuinely changes the future trajectory. At the population level, the same logic applies to school canteens, workplace design, food labelling and urban walkability. Individual will alone cannot carry the weight of a structural transition.

For the person who just looked at a borderline report: the tests above cost less than ₹600 together, the risk factors are knowable, and the window where lifestyle outperforms medication is real. The glucose spiral is slow, quiet, and — at the pre-diabetes stage — eminently stoppable. That is not a small thing.