Bmi Weight(kg) Body mass index Height(m) Category BMI Underweight< 18.50 Normal 18.5-23.99 Overweight≥24(23) Obese ≥28(25) Interpretation varies by ethnic group Because muscle density is greater than fat, BMi may overestimate the body fat content of very muscular people. In addition, bMi may also underestimate the body fat content of people with reduced muscle mass(such as the elderly)
Body Mass Index Category BMI Underweight < 18.50 Normal 18.5 – 23.99 Overweight ≥ 24（23） Obese ≥ 28 (25) 2 Height(m) Weight(kg) BMI • Interpretation varies by ethnic group Because muscle density is greater than fat, BMI may overestimate the body fat content of very muscular people. In addition, BMI may also underestimate the body fat content of people with reduced muscle mass (such as the elderly)
The yy paradox 223 BMI 223 91% BODYFAT 212% Source: Yajnik cs, Yudkin The Y-Y Paradox. Lancet (20043303: 163
“The Y-Y Paradox” 9.1% BODY FAT 21.2% 22.3 BMI 22.3 Source: Yajnik CS, Yudkin J: The Y-Y Paradox. Lancet (2004) 363:163
The two authors share a near identical body-mass index(BMi), but as dual X-ray absorptiometry imagery shows that is where the similarity ends. The second author(figure, right) has substantially more body fat than the first author(figure, left). Lifestyle may be relevant: the first author runs marathons whereas the second author s main exercise Is running to beat the closing doors of the elevator in the hospital every morning. The contribution of genes to such adiposity is yet to be determined, although the possible relevance of intrauterine under-nutrition is supported by the second author's low birthweight The image is a useful reminder of the limitations of BMI as a measure of adiposity across populations
The two authors share a near identical body-mass index (BMI), but as dual X-ray absorptiometry imagery shows that is where the similarity ends. The second author (figure, right) has substantially more body fat than the first author (figure, left). Lifestyle may be relevant: the first author runs marathons whereas the second author's main exercise is running to beat the closing doors of the elevator in the hospital every morning. The contribution of genes to such adiposity is yet to be determined, although the possible relevance of intrauterine under-nutrition is supported by the second author's low birthweight. The image is a useful reminder of the limitations of BMI as a measure of adiposity across populations
Waist circumference Approx Cut-off Waist Circumference(cm) Men Women Caucasian <100 <90 Asian <90 <80 Simple measurement Less problem with the body composition paradox
Waist Circumference Approx Cut-off Waist Circumference (cm) Men Women Caucasian < 100 < 90 Asian < 90 < 80 • Simple measurement • Less problem with the body composition paradox
Body Fat Percentage Gender Ideal range for body fat percentageObesity Below 30 years old Over 30 years (including 30ys Male 14-21% 17-23% 5% Female 17-249% 0-27% >=30% More accurate Complex measurement
Gender Ideal range for body fat percentage Obesity Below 30 years old （including 30ys） Over 30 years Male 14－21% 17－23% >=25% Female 17－24% 20－27% >=30% Body Fat Percentage • More accurate • Complex measurement