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Understanding BMI — Leanova Health
Understanding BMI

Your BMI is a signal.
Not the whole story.

Body Mass Index is a useful starting point for understanding metabolic risk — but for Indians, the thresholds are different, the implications are greater, and the picture is always incomplete without clinical context.

23
BMI at which Indians enter overweight risk — not 25
27.5
Obesity threshold for South Asians — not 30
Higher diabetes risk at the same BMI as Western populations
40%
Of Indians with normal BMI may still have metabolic risk factors
Your journey: Take the First Step Understand the Programme Learn About BMI See Pricing

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Get your BMI, category, and a personalised 12-month weight projection — all in one place.

cm
kg
cm

Measure at the narrowest point of your abdomen. Asian risk threshold: >90cm for men, >80cm for women.

14 25 45+
UnderweightNormalOverweightObese IObese II+
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BMI is one data point. Your Leanova doctor reviews body composition, blood markers, insulin resistance, and hormonal health for a complete picture.

Take the First Step
What is BMI?

A simple number with important context

Body Mass Index is a ratio of your weight to your height squared. It was originally developed in the 1830s by Belgian mathematician Adolphe Quetelet — not as a clinical tool, but as a population-level statistical measure. It became a medical screening tool in the 1970s.

Today, BMI is used by clinicians worldwide as a quick, inexpensive way to identify whether a person's weight may be putting their health at risk. It is a screening tool — not a diagnostic one. A high BMI flags potential risk; it does not diagnose a condition.

How BMI is calculated

The formula is straightforward:

BMI = Weight (kg) ÷ Height (m)²
For example: 75 kg ÷ (1.65 m × 1.65 m) = BMI of 27.5

In imperial units: multiply weight in pounds by 703, divide by height in inches, then divide again by height in inches.

What the numbers mean — for Indians

Standard BMI thresholds were developed using predominantly Western, European populations. Research shows that Indian and South Asian populations develop cardiometabolic complications — insulin resistance, Type 2 diabetes, cardiovascular disease — at significantly lower BMI values.

The World Health Organization and the Indian Council of Medical Research recommend using Asian-specific thresholds for people of South Asian origin:

Underweight < 18.5
Normal weight 18.5 – 22.9
Overweight (Asian threshold) 23.0 – 27.4
Obesity — Class I (Asian threshold) 27.5 – 32.4
Obesity — Class II–III 32.5 +

At Leanova, we apply Asian-specific BMI thresholds for all Indian patients. A BMI of 23 — within the "normal" range by Western standards — is already considered overweight for South Asian populations.

The Indian metabolic profile

Why the same BMI means different things for Indians

Research consistently shows that Indian and South Asian people have a higher proportion of body fat at any given BMI than Western populations. This means that at the same BMI, an Indian person carries more metabolically active visceral fat — the type that drives insulin resistance, inflammation, and cardiometabolic risk.

This is sometimes called "thin-fat syndrome" or TOFI (Thin Outside, Fat Inside) — a pattern where someone appears metabolically normal by Western BMI standards, but is already accumulating visceral fat and developing insulin resistance.

A South Asian person with a BMI of 24 may carry the same cardiometabolic risk as a person of European descent with a BMI of 28–30. This is why Leanova uses Asian-specific thresholds for all Indian patients.

Indians develop Type 2 diabetes on average 10 years earlier than Western populations, often at lower BMI values, with a stronger genetic predisposition to insulin resistance.

Western / WHO Standard thresholds
Underweight
< 18.5
Normal
18.5–25
Overweight
25–30
Obese
≥ 30
vs
Asian / Indian thresholds (Leanova standard)
Underweight
< 18.5
Normal
18.5–23
Overweight
23–27.5
Obese
≥ 27.5
Important limitations

What BMI doesn't tell you

BMI is a useful screening tool, but it has significant limitations — especially when used in isolation. This is why Leanova never relies on BMI alone.

It can't distinguish fat from muscle

A highly muscular person can have a high BMI with very little body fat, while someone with low muscle mass can have a normal BMI but high visceral fat. BMI measures mass — not composition.

It ignores where fat is stored

Visceral fat (stored around the organs, especially the abdomen) is far more dangerous than subcutaneous fat. Two people with the same BMI can have very different fat distribution and very different risk profiles.

It doesn't account for genetics

South Asians have a genetic predisposition to insulin resistance, beta-cell dysfunction, and central adiposity — factors that BMI cannot capture. Family history of diabetes or heart disease significantly changes the risk picture.

It misses metabolic health entirely

Blood sugar regulation, insulin sensitivity, cholesterol ratios, inflammatory markers — none of these are reflected in BMI. A person with a normal BMI can have poorly controlled blood sugar and significant cardiometabolic risk.

It treats all adults the same

BMI uses the same formula for men and women, despite women typically having higher body fat percentages at the same BMI. It also doesn't account for age-related changes in muscle mass and fat distribution.

It's less accurate at height extremes

Because BMI squares height, it tends to overestimate risk in tall individuals and underestimate it in shorter individuals. For very tall or very short people, waist circumference and body composition tests are more informative.

What Leanova assesses instead

The complete metabolic picture

At Leanova, BMI is the starting point — not the endpoint. Our doctors use a comprehensive set of markers to understand your actual cardiometabolic risk.

Body composition analysis

The ratio of fat mass to lean mass — where the fat is stored, and how much of it is visceral. Far more informative than BMI alone.

Fasting insulin and blood glucose

Identifies insulin resistance — often the earliest signal of metabolic dysfunction — before blood sugar even crosses the diabetic threshold.

Full lipid panel

Total cholesterol, LDL, HDL, triglycerides, and non-HDL cholesterol — the complete cardiovascular risk picture, not just total cholesterol.

Thyroid and hormonal markers

Thyroid dysfunction, PCOS-related hormonal patterns, and cortisol dysregulation all affect metabolism and weight — and all go undetected by BMI.

Waist circumference

A stronger predictor of cardiometabolic risk than BMI in South Asians. Asian thresholds: >90cm for men, >80cm for women signal elevated risk.

Full medical and lifestyle history

Family history of diabetes, hypertension, or heart disease. Sleep patterns, stress, movement, and nutrition — all factors that shape your true risk.

Understanding each category

What your BMI category means

Using Asian-specific thresholds — the standard Leanova applies to all Indian patients.

< 18.5
Underweight

Below the healthy range

Being underweight can indicate nutritional deficiency, malabsorption, thyroid conditions, or other underlying health issues. It carries its own set of health risks including bone density loss, immune impairment, and hormonal disruption. Clinical assessment is recommended to identify and address the cause.

18.5–22.9
Normal

Within the healthy range — but not risk-free

A normal BMI by Asian standards is a positive indicator, but it does not guarantee metabolic health. Some people in this range have elevated visceral fat, poor insulin sensitivity, or early cardiometabolic dysfunction — especially if sedentary or with a family history of metabolic disease. Regular monitoring remains important.

23.0–27.4
Overweight

Elevated cardiometabolic risk

At this range, Indian populations begin to show measurably increased risk for insulin resistance, Type 2 diabetes, hypertension, and cardiovascular disease. Early medical intervention — lifestyle modification, metabolic assessment, and where appropriate, clinical treatment — can significantly alter the long-term trajectory. This is the optimal time to act.

27.5–32.4
Obesity I

High risk — medical assessment strongly recommended

Class I obesity in the Indian context is associated with substantially elevated risk for Type 2 diabetes, PCOS, non-alcoholic fatty liver disease, hypertension, and obstructive sleep apnoea. At this stage, lifestyle intervention alone is often insufficient — and clinically supervised treatment, including where indicated pharmacotherapy, produces significantly better outcomes.

32.5 +
Obesity II–III

Very high risk — structured clinical care is indicated

At this range, the health burden is significant and the evidence for medically supervised treatment — including clinically approved pharmacotherapy where appropriate — is strong. Obesity at this level is a chronic medical condition that requires the same clinical rigour as any other serious disease. The biology is the driver, not a lack of willpower.

The formula

How BMI is calculated

The calculation is simple. The interpretation — especially for Indian populations — requires clinical context.

The BMI formula
BMI = Weight (kg) ÷ Height (m)²
Height must be in metres, not centimetres. Convert by dividing cm by 100.
Example: 165 cm → 1.65 m  ·  75 kg ÷ (1.65 × 1.65) = BMI 27.5
01

Convert height to metres

Divide your height in centimetres by 100. 170 cm becomes 1.70 m.

02

Square your height

Multiply your height in metres by itself. 1.70 × 1.70 = 2.89 m².

03

Divide weight by height²

80 kg ÷ 2.89 = BMI of 27.7 — Obesity Class I by Asian standards.

BMI is where the conversation starts.

Your Leanova doctor reviews your complete metabolic picture — not just a single number. Take the first step and we'll reach out within 24 hours.