"Thin-fat" Indians: why a normal BMI can hide high risk
Why many slim Indians carry hidden belly fat, what Pune's "thin-fat babies" showed, the Indian BMI and waist numbers, and what helps.
Written for India. Reading from the US? US versionComing soon
Many Indians carry more body fat, especially around the belly, than their BMI suggests. Experts call this the "thin-fat" pattern. In English health records, South Asians had the diabetes risk of a white BMI of 30 at just 23.9. India's own cut-offs count 23 as overweight, and add a waist check.
Key takeaways
- "Thin-fat" Indians have a normal BMI but extra body fat: in the Y-Y paradox, two doctors with a BMI of 22.3 had 21.2% vs 9.1% body fat.2
- In 1.47 million English health records, South Asians reached the type 2 diabetes risk of a white BMI of 30 at a BMI of 23.9.13
- India's 2009 consensus calls a BMI of 18.0–22.9 healthy, 23–24.9 overweight and 25 or more obesity, and adds waist levels of 90 cm (35.4 inches) (men) and 80 cm (31.5 inches) (women).10
- Exercise was linked to about 6% less fat around the organs even without weight loss, in a review of 117 studies.20
- India's ESI 2025 guideline says a doctor may consider weight medicine above a BMI of 27, or above 25 with a related condition, so it does not cover a normal BMI.3
On this page
- What does "thin-fat" mean?
- Does the thin-fat pattern begin at birth?
- Do Indians carry more fat at the same BMI?
- How much lower is the BMI where diabetes risk rises?
- What are the Indian BMI and waist cut-offs?
- How is hidden body fat measured?
- What helps if you are thin-fat?
- Where do medicines fit for a thin-fat person?
- Questions people ask
- How we researched this
What does "thin-fat" mean?
It means a normal body mass index (BMI) but too much body fat, often around the belly and organs.3,10
BMI is your weight in kg divided by your height in metres, squared. India's Endocrine Society (ESI) lists other names for it: "normal weight obesity", "metabolic obesity" and "skinny fat".3 It says South Asians tend to develop the health problems of obesity at a lower BMI.3
The Y-Y paradox. In January 2004, two doctors published a short note in The Lancet.1 Chittaranjan Yajnik from Pune and John Yudkin from the UK had the same BMI, 22.3.2 A body scan (DEXA) measured their fat. DEXA is a low-dose X-ray that measures fat and muscle. It showed 21.2% body fat for Yajnik and 9.1% for Yudkin.2
That is more than twice the fat at the same BMI.25 Yudkin ran marathons, which also matters.2 It is one comparison of two men, not a study, but larger studies since point the same way.3
How common is it? Studies define it in different ways, so the numbers aren't directly comparable.
- Chennai: 15% of 2,350 adults had a BMI under 25 but a cluster of risk factors (metabolic syndrome).4
- Mumbai: 16% of 269 young adults had a normal BMI but high body fat, measured with skinfold callipers.5
- Kerala: 32% of 1,147 adults at high risk of diabetes had a normal BMI but high body fat.6
In the Kerala group, 20% of the thin-fat people had type 2 diabetes. That was close to the 19% in people with obesity. It was more than double the 8% in people with normal fat.6
Does the thin-fat pattern begin at birth?
Possibly. In a Pune study, Indian babies were smaller than British babies in every measure. But they kept relatively more fat.7
Researchers measured 631 babies born in six villages near Pune and compared them with 338 babies born in Southampton, UK.7 The Pune babies weighed 2.7 kg on average, vs 3.5 kg.7 Their mothers had an average BMI of 18.2, vs 23.4.7
The biggest gap was belly size (abdominal circumference). The smallest gap was the skinfold under the shoulder blade, a measure of fat.7 The authors said the babies had "low muscle mass, but preserve body fat". They added that this "may persist" and raise later diabetes risk.7
At about age 6, the Pune children had a lower BMI than white UK children. Yet DEXA showed more body fat: 4.5 percentage points more in boys.8 They were also more resistant to insulin, the hormone that moves sugar into cells.8
A caution. In the same Pune children, the thin-fat body shape at birth did not predict heart risk factors at age 6.9 Faster growth after infancy did.9 So birth size is part of the story, not a fixed fate.
Do Indians carry more fat at the same BMI?
Yes, on average. India's 2009 consensus says Asian Indians carry more body and belly fat than white Europeans at similar BMIs.10
The consensus asked which BMI matches too much fat: 25% body fat in men, 30% in women.10 In Indian studies, that BMI was mostly 21.5–24 for men and 19–24 for women.10 Those are well below the Western obesity line of 30.
Two small US studies looked inside the body with CT scans.
In the first study, poorer insulin action went with visceral fat, not with fat under the skin.11 Both studies are small, so treat them as a pointer, not a measurement for you.
How much lower is the BMI where diabetes risk rises?
About 6 to 8 BMI points lower, in two large UK studies. South Asians reached the diabetes risk of a white BMI of 30 at 23.9 or 22.0.13,14
England's GP records. This study followed 1,472,819 adults for a median of 6.5 years, including 75,956 South Asians.13 It counted new cases of type 2 diabetes.13
UK Biobank. This study looked at 490,288 adults aged 40–69 at one point in time, including 9,631 South Asians.14 South Asians had the diabetes rate of a white BMI of 30 at a BMI of 22.0.14 For waist, a white man's 102 cm (40.2 inches) matched 79 cm (31.1 inches) in South Asian men. A white woman's 88 cm (34.6 inches) matched 70 cm (27.6 inches).14
In South Asia. The CARRS study followed 3,136 adults aged 45 and over in Chennai, Delhi and Karachi.15 Among those with a BMI under 25, South Asian men got diabetes about 3 times as often as white Americans. South Asian women got it 5.3 times as often.15 The authors suggest lower insulin output, not only insulin resistance, may explain it.15
India's 2009 consensus cites an Indian study of people with a BMI under 25.10 At least one heart risk factor was found in 66% of the men and 88% of the women.10
What are the Indian BMI and waist cut-offs?
India's 2009 consensus sets a healthy BMI at 18.0–22.9, overweight at 23–24.9 and obesity at 25 or more. It adds two waist levels.10
A 2025 proposal from the India Obesity Commission goes further. It is a proposal, kept separate here from the 2009 cut-offs.16
| Measure | 2009 consensus (in use) | 2025 proposal |
|---|---|---|
| BMI | Healthy 18.0–22.9; overweight 23–24.9; obesity 25 or more10 | Obesity above 23: Stage 1 if organs work normally, Stage 2 with a large waist plus symptoms or a related disease16 |
| Waist, men | Above 78 cm (30.7 in): avoid weight gain, stay active. Above 90 cm (35.4 in): seek medical help10 | 90 cm (35.4 in) or more16 |
| Waist, women | Above 72 cm (28.3 in): avoid weight gain, stay active. Above 80 cm (31.5 in): seek medical help10 | 80 cm (31.5 in) or more16 |
| Waist ÷ height | Not used | Above 0.516 |
Sources: Misra et al., JAPI 2009; Misra et al. (India Obesity Commission), Diabetes Metab Syndr 2025. Checked 5 October 2026.
The 2009 consensus says BMI and waist should be used together, with equal weight.10 That matters for thin-fat people, whose BMI can look fine while the waist doesn't.
A worked example. Take someone 1.65 m tall who weighs 60 kg. Their BMI is 22, inside the healthy range. If their waist is 85 cm (33.5 inches), waist ÷ height is 85 ÷ 165 = 0.52, above the 0.5 line. This is our arithmetic.
For a woman, 85 cm (33.5 inches) is also above the 80 cm (31.5 inches) level. For a man, it is below 90 cm (35.4 inches) but above 78 cm (30.7 inches).10 The full guide is Guide 1: weight and health in Indians. Short Answers are on the way: What is a healthy BMI for Indians? and What waist size is too high for Indians?.
How is hidden body fat measured?
A tape measure is the everyday test. A DEXA scan measures fat and muscle directly, and ESI keeps it for selected patients.16,18
Waist, the Indian way. Measure before eating, standing straight. Use a tape that doesn't stretch, level, just above the hip bone, at the end of a normal breath out.16 Then divide your waist by your height, both in cm.
The 2025 paper says waist-to-height should be preferred over waist-to-hip.16 It cites a review of 30 studies and over 300,000 people. That review backs the 0.5 line across sexes and ethnic groups.16
Direct fat measurement. The 2025 Lancet Commission says BMI should only screen, not judge one person's health.17 Extra fat should be confirmed by a waist measure or, "where available", direct fat measurement such as DEXA or bioimpedance.17 Bioimpedance machines send a tiny current through the body; the Kerala study used one.6
ESI's 2022 guideline lists a DEXA body-composition scan as a test "in selected patients", not for everyone.18 One private Hyderabad hospital lists ₹2,500–4,500 for a DEXA body-composition scan (checked 5 Oct 2026).19
Enter height, weight and waist. See your BMI, waist and waist-to-height against Indian numbers. No sign-up.
What helps if you are thin-fat?
Regular exercise, including strength work, has the clearest evidence for belly fat. Lifestyle programmes cut diabetes in Indians, but one Kerala trial in thin-fat people found only small gains.20,21,22
Exercise targets the fat that matters. A review of 117 studies (4,815 people) compared exercise with dieting.20 Without any weight loss, exercise was linked to 6.1% less visceral fat; diet alone, 1.1%.20 The authors warn that the scale may not show the change.20
Keep muscle. A 2026 Indian editorial says Indian studies find lower muscle mass alongside high fat.25 It cites a review where resistance exercise improved body make-up and strength in people with low muscle and high fat.25 The consensus suggests strength work on 2–3 days a week, 8–12 repetitions per set.10
Lifestyle and diabetes in India. The Indian Diabetes Prevention Programme enrolled 531 people with high blood sugar after a glucose drink.21 They were described as "younger, leaner" than people in Western trials, with an average BMI of 25.8.21 Over 3 years, 39.3% on lifestyle advice developed diabetes, vs 55.0% in the control group.21
The honest gap. In the Kerala programme, 292 thin-fat adults were split into a peer-led lifestyle group or a control group.22 After 2 years, only systolic blood pressure and "good" HDL cholesterol improved slightly. Blood sugar and other fats did not differ.22 ESI calls this group "resistant to change" with lifestyle alone.3
When diabetes has already arrived. A small UK study, ReTUNE, enrolled 20 people with type 2 diabetes and a BMI under 27.23 They used a supervised 800-calorie formula diet in short cycles. Average BMI fell from 24.8 to 22.4, and 70% went into remission.23,24 It was not an Indian study.
Food changes on a medicine are covered in an Indian diet on a GLP-1 and protein for Indian vegetarians. All the options side by side are in Guide 3: your options.
Where do medicines fit for a thin-fat person?
Mostly outside current thresholds. ESI 2025 says a doctor may consider weight medicine above BMI 27, or above 25 with a related condition.3
- GLP-1 medicines are prescription-only. A government statement on 1 Apr 2026 said only endocrinologists, internal-medicine specialists and cardiologists can prescribe them.31 CDSCO expert-committee minutes attach a similar condition to some approvals (endocrinologist or internal-medicine specialist), but we found no rule covering every brand.32,33
- They have serious risks as well as common side effects: Guide 5: Side effects and risks.
- Guideline numbers describe what a doctor may consider. A doctor decides, case by case.
ESI's examples of related conditions are high blood pressure, abnormal cholesterol, type 2 diabetes and sleep apnoea.3 ESI also says the point to treat "is not based on BMI alone".3 A normal BMI sits below both thresholds.
The trials didn't test normal BMI. STEP 1 was the main weight trial of semaglutide 2.4 mg (Wegovy). It enrolled people with a BMI of 30 or more, or 27 with a weight-related condition.26 Lilly's India launch gave the same BMI levels for Mounjaro's weight use.27 We found no GLP-1 weight trial in people with a normal BMI.
Type 2 diabetes is different. Ozempic's US label lists it for blood-sugar control in adults with type 2 diabetes, alongside diet and exercise.28 Mounjaro's Indian launch named the same diabetes use.27 So a thin-fat person who develops diabetes may hear about these medicines as diabetes treatment. The type 2 diabetes path covers that route.
The 2025 proposal. For Stage 1, it says lifestyle measures "would usually be sufficient".16 Medicine "could be an option" for some, such as people with a strong family history of diabetes or heart disease.16 For Stage 2 without diabetes, it recommends orlistat, an older pill. Where type 2 diabetes is present, it puts GLP-1 medicines first.16 That route is compared in orlistat vs GLP-1 medicines.
Muscle is the extra worry. The 2026 Indian editorial says lean mass makes up "to the tune of 40%" of any weight loss, GLP-1 medicines included.25 For Indians who already have low muscle, it warns this can tip into muscle loss (sarcopenia).25 More is in muscle loss and loose skin on GLP-1 medicines.
- Stomach effects are common. In STEP 1, 4.5% stopped semaglutide for stomach side effects, vs 0.8% on placebo.26
- Pancreatitis (an inflamed pancreas) is a label warning. The sign is severe stomach pain that won't go away, sometimes reaching the back.28,29
- Gallbladder problems, such as gallstones, are in the labels.29,30
- Low blood sugar is more likely with insulin or a sulfonylurea, a type of diabetes tablet.28,29
- Dehydration from vomiting or diarrhoea can injure the kidneys.28,30
- Thyroid warning. Ruled out by the US labels for people with a personal or family history of MTC, a thyroid cancer, or MEN 2; tell your doctor if this applies. The semaglutide labels say to stop at least 2 months before a planned pregnancy.28,29
For the full "when not to" picture, read Guide 4: should I consider a GLP-1?
Questions people ask
Can a slim person get type 2 diabetes?
Yes. In one study, South Asians with a BMI under 25 got diabetes 3 to 5 times as often as similar white Americans.15
What is the Y-Y paradox?
It is a 2004 Lancet note by two doctors, Yajnik and Yudkin. Both had a BMI of 22.3, but body scans showed 21.2% vs 9.1% body fat.1,2
What BMI is healthy for Indians?
India's 2009 consensus calls 18.0–22.9 healthy, 23–24.9 overweight and 25 or more obesity. A 2025 proposal would count obesity from above 23.10,16
What waist size is too high for Indians?
The 2009 consensus asks men with a waist above 90 cm (35.4 inches) and women above 80 cm (31.5 inches) to seek medical help. It suggests avoiding weight gain above 78 cm (30.7 inches) (men) and 72 cm (28.3 inches) (women).10
Is waist-to-height ratio better than BMI?
It shows belly fat, which BMI misses. The 2025 Indian proposal uses a ratio above 0.5 as a sign of belly fat. It is used with BMI, not instead of it.16
Can a doctor prescribe Ozempic if my BMI is normal?
For weight, India's ESI 2025 guideline says a doctor may consider medicine above a BMI of 27, or above 25 with a weight-related condition. The weight trials enrolled higher BMIs. For type 2 diabetes, Ozempic is a blood-sugar medicine, and a doctor decides.3,26,28
How we researched this
We read the 2009 Indian consensus and the 2025 India Obesity Commission paper in full. We also read the ESI 2025 update and the 2025 Lancet Commission. We read the Pune, Chennai, Mumbai and Kerala studies, CARRS, and both UK BMI-equivalence studies.
The brief for this post paired "23.9" with UK Biobank. That figure comes from England's GP records; UK Biobank gave 22.0. We show both. We could not open the original Y-Y note, so its numbers come from two papers that reproduce them.
We cut claims we saw only on companies that sell body-fat scanners. The ReTUNE study is a small UK study, reported by Diabetes UK and its lead author.
Before you move on
- A normal BMI can hide extra body fat, especially around the belly, in many Indians.
- Indian cut-offs: BMI 23 is overweight, 25 is obesity, and waist matters as much as BMI.
- Waist ÷ height above 0.5 is a simple flag you can work out with a tape measure.
- Daily activity with strength work has the best evidence for belly fat. In one Kerala trial, lifestyle alone helped thin-fat people only a little.
- ESI 2025 says a doctor may consider weight medicine above a BMI of 27, or above 25 with a weight-related condition; diabetes treatment is a separate route.
More from the India blog
The monthly India update
An independent guide to GLP‑1 medicines. We don't sell medicines, take drug-company money or earn clinic commissions. Once a month: new brands, price changes, approvals and recalls. How we write
Sources
- Yajnik CS, Yudkin JS. The Y-Y paradox. Lancet 2004;363(9403):163. doi:10.1016/S0140-6736(03)15269-5 · PMID 14726172
- Kishore BK. Reverse epidemiology of obesity paradox: fact or fiction? Physiol Rep 2024;12(21):e70107. Reproduces the Y-Y paradox figures. doi:10.14814/phy2.70107 · PMC11521792
- Madhu SV, Kapoor N, Das S, Raizada N, Kalra S. ESI clinical practice guidelines for the evaluation and management of obesity in India: an update (2025). Indian J Endocrinol Metab 2025;29(4):355–65. doi:10.4103/ijem.ijem_680_25 · PMC12410957
- Geetha L, Deepa M, Anjana RM, Mohan V. Prevalence and clinical profile of metabolic obesity and phenotypic obesity in Asian Indians. J Diabetes Sci Technol 2011;5(2):439–46. doi:10.1177/193229681100500235 · PMID 21527117
- Hadaye RS, Manapurath RM, Gadapani BP. Obesity prevalence and determinants among young adults, with special focus on normal-weight obesity; a cross-sectional study in Mumbai. Indian J Community Med 2020;45(3):358–62. doi:10.4103/ijcm.IJCM_408_19 · PMID 33354019
- Kapoor N et al. Prevalence of normal weight obesity and its associated cardio-metabolic risk factors: results from the baseline data of the Kerala Diabetes Prevention Program (KDPP). PLoS One 2020;15(8):e0237974. doi:10.1371/journal.pone.0237974 · PMID 32841271
- Yajnik CS et al. Neonatal anthropometry: the thin-fat Indian baby. The Pune Maternal Nutrition Study. Int J Obes Relat Metab Disord 2003;27(2):173–80. doi:10.1038/sj.ijo.802219 · PMID 12586996
- Lakshmi S et al. Differences in body composition and metabolic status between white U.K. and Asian Indian children (EarlyBird 24 and the Pune Maternal Nutrition Study). Pediatr Obes 2012;7(5):347–54. doi:10.1111/j.2047-6310.2012.00063.x · PMID 22941936
- Joglekar CV et al. Newborn size, infant and childhood growth, and body composition and cardiovascular disease risk factors at the age of 6 years: the Pune Maternal Nutrition Study. Int J Obes 2007;31(10):1534–44. doi:10.1038/sj.ijo.0803679 · PMID 17653070
- Misra A et al. Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management. J Assoc Physicians India 2009;57:163–70. PMID 19582986
- Banerji MA et al. Body composition, visceral fat, leptin, and insulin resistance in Asian Indian men. J Clin Endocrinol Metab 1999;84(1):137–44. doi:10.1210/jcem.84.1.5371 · PMID 9920074
- Raji A, Seely EW, Arky RA, Simonson DC. Body fat distribution and insulin resistance in healthy Asian Indians and Caucasians. J Clin Endocrinol Metab 2001;86(11):5366–71. doi:10.1210/jcem.86.11.7992 · PMID 11701707
- Caleyachetty R et al. Ethnicity-specific BMI cutoffs for obesity based on type 2 diabetes risk in England: a population-based cohort study. Lancet Diabetes Endocrinol 2021;9(7):419–26. doi:10.1016/S2213-8587(21)00088-7 · PMID 33989535
- Ntuk UE, Gill JM, Mackay DF, Sattar N, Pell JP. Ethnic-specific obesity cutoffs for diabetes risk: cross-sectional study of 490,288 UK Biobank participants. Diabetes Care 2014;37(9):2500–7. doi:10.2337/dc13-2966 · PMID 24974975
- Narayan KMV et al. Incidence and pathophysiology of diabetes in South Asian adults living in India and Pakistan compared with US blacks and whites (CARRS and ARIC). BMJ Open Diabetes Res Care 2021;9(1):e001927. doi:10.1136/bmjdrc-2020-001927 · PMC8006839
- Misra A, Vikram NK, Ghosh A et al.; India Obesity Commission. Revised definition of obesity in Asian Indians living in India. Diabetes Metab Syndr 2025;19:102989. Declared interests: the lead author declares grants, lecture fees and travel from Novo Nordisk and Eli Lilly, and from Indian makers including USV, Lupin, Cipla and Glenmark; a second author declares grants and lecture fees from Cipla, USV and Lupin (paper's own declaration). doi:10.1016/j.dsx.2024.102989 · PMID 39814628
- Rubino F et al. Definition and diagnostic criteria of clinical obesity (Lancet Diabetes & Endocrinology Commission). Lancet Diabetes Endocrinol 2025;13:221–62. Declared interests: most of the 56 authors declare fees, grants or other payments from Novo Nordisk, and many also from Eli Lilly; one also declares grants and lecture fees from Indian makers including USV, Lupin, Cipla, Glenmark and Zydus (paper's own declaration). doi:10.1016/S2213-8587(24)00316-4 · PMC11870235
- Madhu SV et al. (Endocrine Society of India). ESI clinical practice guidelines for the evaluation and management of obesity in India. Indian J Endocrinol Metab 2022;26:295–318. Table 8. doi:10.4103/2230-8210.356236 · PMC9519829
- Yashoda Hospitals, Hyderabad. DEXA scan cost page, "DEXA Scan – Body Composition Analysis: Rs. 2,500 – Rs. 4,500". Hospital price list, checked 5 Oct 2026 (not linked: booking page).
- Verheggen RJ et al. A systematic review and meta-analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue. Obes Rev 2016;17(8):664–90. doi:10.1111/obr.12406 · PMID 27213481
- Ramachandran A et al. The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1). Diabetologia 2006;49:289–97. doi:10.1007/s00125-005-0097-z · PMID 16391903
- Kapoor N et al. Effect of a peer-led lifestyle intervention on individuals with normal weight obesity: insights from the Kerala Diabetes Prevention Program. Clin Ther 2020;42(8):1618–24. doi:10.1016/j.clinthera.2020.06.007 · PMID 32718783
- Diabetes UK. DUKPC Digest day 5: ReTUNE study, type 2 remission possible for lower body weights. 1 Apr 2022. diabetes.org.uk
- Taylor R. Aetiology of type 2 diabetes: an experimental medicine odyssey. Diabetologia 2025;68(7):1375–89. The author declares lecture fees from Eli Lilly and Novo Nordisk (paper's own declaration). doi:10.1007/s00125-025-06428-0 · PMID 40316731
- Madhu SV, Raizada N. The Indian obesity paradox: low in muscle, high in fat (editorial). Indian J Endocrinol Metab 2026;30(2):115–8. doi:10.4103/ijem.ijem_245_26 · PMC13229243
- Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med 2021;384:989–1002. Funded by Novo Nordisk. doi:10.1056/NEJMoa2032183 · PMID 33567185
- IPP Bureau. Lilly launches Mounjaro in India for treatment of obesity and type 2 diabetes. Indian Pharma Post, 24 Mar 2025. indianpharmapost.com
- Ozempic (semaglutide) US Prescribing Information, revised 05/2026. US label, not the Indian one. novo-pi.com/ozempic.pdf
- Wegovy (semaglutide) US Prescribing Information, revised 06/2026. US label, not the Indian one. novo-pi.com/wegovy.pdf
- Zepbound (tirzepatide) US Prescribing Information, revised 08/2026. US label, not the Indian one. pi.lilly.com/us/zepbound-uspi.pdf
- PIB Research. GLP-1 Drugs: Use, Risks, and Regulation. Government of India backgrounder, 1 Apr 2026. static.pib.gov.in (PDF)
- CDSCO. Recommendations of the Subject Expert Committee (Endocrinology & Metabolism), meeting of 20–21 April 2023. Item 1, tirzepatide. PDF · Archived copy
- CDSCO. Recommendations of the Subject Expert Committee (Endocrinology & Metabolism), meeting of 13–14 February 2024. Items 3–4, semaglutide. PDF · Archived copy
Last checked 5 Oct 2026 · Next review due 5 Oct 2027 · Report an error
How this post was made. Written by the GLP Guidebook team from the sources above. It's general information, not medical advice. Talk to a qualified doctor before starting, stopping or changing any medicine. How we write