New research changes how obesity is understood for Thai health planning. A study published on June 26, 2025 in the Annals of Family Medicine finds that body fat percentage (BF%) more accurately predicts both all-cause and cardiovascular mortality than body mass index (BMI), especially among adults aged 20 to 49. The findings could influence how Thai clinicians screen for health risks across the country.
For decades, BMI has been the standard metric in Thai hospitals and clinics for obesity screenings, workplace wellness programs, and national health surveys. BMI relies on height and weight and does not distinguish fat from muscle. The latest study shows BF% measured with bioelectrical impedance analysis (BIA) provides a clearer picture of long-term mortality risk and is increasingly accessible in primary care.
The international team analyzed data from over 4,000 adults who participated in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004. They compared 15-year mortality risks using BMI and BF%, with BF% measured by BIA. The results were striking: men with BF% at or above 27% and women at or above 44% faced about a 78% higher risk of death from any cause and roughly 2.6 times the risk of cardiovascular death compared with those with healthier BF%. In contrast, BMI did not show a statistically significant link to mortality in the same group.
One study author highlighted the practicality of BIA devices, noting they deliver results in under a minute and are far more affordable than DEXA scans, which are rarely used in routine primary care. Even older BIA technology produced strong signals, underscoring the method’s robustness and potential for wide adoption in basic health checks.
The findings align with Thai clinicians’ long-standing observations that high BF%, not just high weight, drives many non-communicable diseases rising in Thailand—such as heart disease, diabetes, and metabolic syndrome. Thai endocrinologists and nutritionists have warned that individuals with a “normal” BMI can still carry high visceral fat and face silent risks like fatty liver and hypertension.
The study strengthens calls for updating Thai screening practices in schools, workplaces, and hospitals, and for investing in BIA technology. While the Ministry of Public Health currently emphasizes BMI in national health checks, BF% measurement is not yet routine. Lead author projections suggest BF% may become standard care once consensus thresholds for healthy and unhealthy BF% are established through larger prospective trials.
Affordability further supports broader adoption in a middle-income country like Thailand. DEXA scanners are expensive, while affordable BIA devices span a wide price range, making the technology feasible for public hospitals, private clinics, and many community health centers. A senior official from Thailand’s National Health Security Office notes that rapid, accurate body composition assessments could sharpen the targeting of public health interventions.
However, the researchers caution that there is no universal agreement on BF% cutoffs by age, gender, and ethnicity. Interpreting BIA requires some training, and how results inform clinical decisions varies. In Thailand, where genetic, dietary, and lifestyle factors differ from Western populations, local studies are essential to define thresholds that fit the nation’s diverse population. A policy paper from a Bangkok university similarly urged large Thai cohort studies to calibrate BF% cutoffs for local contexts.
The new evidence adds urgency to revisiting BMI’s limitations, a concept rooted in 19th-century Europe and never intended as a diagnostic tool. As Thailand urbanizes and diets shift, the TOFI (thin outside, fat inside) concept gains traction among health professionals. TOFI individuals can carry hidden cardiometabolic risks that BMI may miss. This pattern is emerging in other Asian populations as well, prompting revisions to screening guidelines to focus on body composition alongside weight.
Thai health professionals respond with cautious optimism. A senior advisor to the national obesity association notes, “This evidence aligns with what we’ve observed in clinics: BMI often fails to capture risk, particularly for patients who do not appear overweight but have high body fat and metabolic abnormalities.” The advisor adds that wider access to BF% testing could help address Thailand’s growing burden of diabetes and cardiovascular disease, especially as the population ages.
In terms of policy, the Ministry of Public Health has piloted more advanced body composition measures in select regional hospitals but has not scaled them nationwide. Some municipal health clinics in Bangkok, Chiang Mai, and Khon Kaen have piloted BF% screening for high-risk groups. A Bangkok Metropolitan Administration official says the city is monitoring global guidelines and would consider incorporating BF% in future health campaigns if consensus emerges.
Looking ahead, broader acceptance of BF% could reshape health insurance considerations and school health curricula. Some private hospitals already advertise full body composition analysis as part of executive health packages, while weight-management clinics tailor programs based on BF%. Market interest in affordable BIA devices is likely to rise, especially among Thailand’s health-conscious younger adults.
Thai society holds nuanced views on body image, influenced by Buddhist health principles and evolving global standards. Studies from Thai universities show growing interest in holistic wellness, including fat distribution and muscle mass, while warning against body-shaming and extreme dieting. The Ministry of Education encourages schools to pair any new assessments with positive health messaging to avoid stigmatization.
Clear, actionable steps for readers and stakeholders include:
- Individuals: If a BIA test is available, request a body composition analysis during checkups. Focus on reducing excess body fat through regular physical activity and balanced diets rich in fruits, vegetables, and lean proteins.
- Clinicians: Consider BF% alongside BMI in assessments, especially for patients with normal BMI but metabolic risk factors. Engage management to explore feasible BF% implementation strategies.
- Policymakers: Promote pilot BF% programs in public hospitals and community centers. Support local research to establish healthy BF% ranges for Thais of different ages and backgrounds.
- Educators and media: Promote awareness that body composition matters, not just weight, and advocate for respectful health messaging to prevent stigma.
As Thailand faces rising non-communicable diseases amid lifestyle changes, this study points toward a health paradigm that prioritizes true body composition over weight alone. A holistic approach to wellness can help Thais take informed steps toward better long-term health.
For further context, research discussions reference ongoing global conversations on body fat versus BMI, with international and regional studies informing local dialogue. Data and insights from Thai health experts emphasize the need to adapt global findings to Thailand’s unique population.