What is insulin resistance?
Insulin is a hormone produced by the pancreas that allows cells to take up glucose from the bloodstream and use it for energy. In insulin resistance, cells respond poorly to insulin's signals. The pancreas compensates by producing more insulin. Blood glucose levels may remain normal for years — this is called compensated insulin resistance — but the elevated insulin itself has metabolic consequences.
Chronic hyperinsulinaemia (persistently high insulin) promotes fat storage, particularly in the abdomen, and inhibits fat breakdown. It also drives hunger signals and can trigger cravings for refined carbohydrates. A patient in this state may eat less, exercise more, and still find weight difficult to lose — not because they are doing something wrong, but because their metabolic environment makes weight loss physiologically harder.
Why Indian patients are at particular risk
Indian adults develop type 2 diabetes at lower BMIs than Western populations — the Asian BMI cut-offs for metabolic risk are meaningfully lower than the global standard. An Indian adult at a BMI of 23 may carry the metabolic risk of a European adult at a BMI of 27.
This phenomenon — sometimes called the "thin-fat Indian" — reflects differences in body composition. Indian adults tend to carry a higher proportion of body fat, and specifically visceral fat, relative to their total body weight. Visceral fat is the metabolically active fat that surrounds abdominal organs and is most strongly associated with insulin resistance.
These differences have direct clinical implications: standard BMI thresholds and reference ranges developed in Western populations may underestimate metabolic risk in Indian patients.
The evaluation that matters
A comprehensive metabolic assessment for a patient with weight-related concerns should include:
Fasting glucose and HbA1c. Fasting glucose identifies impaired fasting glucose (a precursor to diabetes); HbA1c provides a three-month average of blood glucose levels. Together they identify where on the glucose metabolism spectrum a patient sits.
Fasting insulin and HOMA-IR. HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) is calculated from fasting glucose and fasting insulin. A HOMA-IR above 2.5–3.0 in the Indian population suggests significant insulin resistance, even if fasting glucose is normal. This test is not routinely ordered in standard health check-ups and is often the missing piece of a patient's metabolic picture.
Lipid panel with ApoB if available. Insulin resistance is associated with elevated triglycerides, low HDL, and small dense LDL particles — the pattern of dyslipidaemia most predictive of cardiovascular risk. ApoB measures the number of atherogenic particles more accurately than LDL-cholesterol alone.
Liver function tests. Non-alcoholic fatty liver disease (NAFLD) is strongly associated with insulin resistance and is prevalent in Indian adults. Elevated ALT is a common early finding.
Thyroid panel. Hypothyroidism contributes to weight gain and fatigue independent of insulin resistance. The two conditions can coexist, and addressing only one may give a partial response.
What insulin resistance looks like clinically
The following clinical features suggest insulin resistance even when fasting glucose is normal:
- Central obesity: waist circumference above 90 cm in Indian men or 80 cm in Indian women
- Acanthosis nigricans: darkened, velvety skin in body folds (neck, armpits, groin) — a visible skin sign of chronic hyperinsulinaemia
- PCOS in women: insulin resistance is present in the majority of PCOS patients and contributes substantially to its metabolic features
- Family history of type 2 diabetes: first-degree relatives with diabetes substantially increase risk
- Fatigue after carbohydrate-heavy meals: a post-meal energy crash followed by hunger is a functional consequence of exaggerated insulin response
The limits of weight management without metabolic evaluation
Dietary interventions and physical activity improve insulin sensitivity and are part of any comprehensive plan. But a patient with significant insulin resistance who has not had a metabolic assessment may not understand why standard approaches have not worked — and may blame themselves for a problem that has a measurable biological basis.
The starting point for effective weight management in a metabolically complex patient is not a diet plan. It is an evaluation that identifies what is driving the difficulty — and builds a plan that addresses the mechanism, not just the number on the scale.