BMI isn't accurate for Aboriginal people because they often have different body compositions, with higher body fat percentage at the same BMI as Caucasians, and body proportions (like longer legs) that skew the results; plus, genetic predispositions and social determinants of health (like food access, housing) create unique health profiles that BMI doesn't capture, requiring broader measures like waist-to-hip ratios for better risk assessment, note HealthBulletin.
Due to differences in body proportion, BMI may not describe the same degree of unhealthy weight in populations other than Caucasian.
For example, people of South Asian descent on average have smaller body frames and fat is distributed differently than for those of European descent. (In fact, they may develop type 2 diabetes at lower BMIs than people of European descent.) Age can deem BMI inaccurate, too.
Experts have also pointed out that BMI fails to take into account factors such as how much fat versus muscle a patient has, the distribution of fat in their body (typically, fat around the waist increases disease risk more than fat in other places), and their metabolic health.
Accuracy of NIH-based cutoff value to define obesity
The sensitivity was significantly higher in black women (75.0%; 95% CI, 65.5–82.6%) compared with white (47.8%; 95% CI, 38.7–57.0%) and Hispanic women (53.9%; 95% CI, 45.7–61.8%; P<. 001 both for black vs. white and black vs. Hispanic).
But BMI Isn't Everything
According to Dr. Cerna, for some people, BMI can be skewed. “If you have a lot of muscle mass, such as in athletes and bodybuilders, your BMI will be overestimated. In seniors and people with less muscle mass, BMI may be underestimated,” said Dr.
BMI-adiposity relations appear to vary significantly across race/ethnic groups, but a collective critical analysis of these effects establishing their magnitude and underlying body shape/composition basis is lacking.
For the following groups of people, BMI is not an accurate measure: Some ethnic groups including Aboriginal and/or Torres Strait Islander Peoples, and people of Asian/South Asian descent. Women who are pregnant. People 19 years of age or younger.
We include ethnicity in BMI calculations to account for varying health risks across different populations, as people from Asian, Black, and other minority ethnic backgrounds may face increased risks of chronic conditions like type 2 diabetes at lower BMI levels compared to white populations.
Results: Obesity prevalence was the highest in non-Hispanic AIAN (44.0%; 95% CI, 38.2%–50.1%), followed by 42.7% (95% CI, 40.5%-44.9%) in non-Hispanic Black adults. Compared to other groups, non-Hispanic Asian adults reported the highest fruit and vegetable intake.
The most important areas of health concern are:
Comparisons in anthropometry show that Asians had more subcutaneous fat than did whites and had different fat distributions from whites. Asians had more upper-body subcutaneous fat than did whites. The magnitude of differences between the two races was greater in females than in males.
Studies have also shown that BMI can mislabel a person's health when compared to objective measures, like results from tests for cholesterol and blood-sugar levels. “Despite assumptions we've come to accept as facts, the evidence linking weight and health is inconsistent,” Russell says.
In 2018–19, 71% (381,800) of Indigenous Australians aged 15 and over had a BMI in the overweight (25–29.9) or obese (>30.0) range (29% were overweight and 43% obese). A further 25% (133,500) had a BMI in the normal weight range (18.5–24.9) and 4% (20,800) were in the underweight category (<18.5).
Recently, however, some researchers and clinicians have been questioning BMI's value. The number does not capture a person's muscle mass; where on their body fat is stored; or how their race, ethnicity and gender affect the complex relationship between their body composition and health risks.
The BMI calculation is just one measure of health. It cannot tell the difference between muscle and fat. For example, if you have a lot of muscle, you may be classed as overweight or obese despite having low body fat. This is why you may get a better idea of your overall health from measuring your waist.
A BMI between 18.5 and 25 kg/m² indicates a normal weight. A BMI of less than 18.5 kg/m² is considered underweight. A BMI between 25 kg/m² and 29.9 kg/m² is considered overweight. A BMI of 30 kg/m² or higher is considered obese.
One issue is that BMI was developed based on the bodies of non-Hispanic white men; it may not provide consistently accurate results for people who fall into other categories of sex, ethnicity, and race.
The traditional diet in Japan is built around a base of rice and other grains, with plentiful consumption of vegetables and fruits, and also fish, but relatively little animal fat, meat and sweets. In Japan, the presentation of the food is very important, and particular attention is given to the colors and textures.
Among men, non-Hispanic African Americans are reported to have an obesity prevalence of 36.9% and Hispanics have the highest prevalence at 43.1% [4••], compared to non-Hispanic white and non-Hispanic Asian women and men (38.0, 14.8, 37.9, and 10.2%, respectively) [4••].
A few people have high BMIs but don't have much body fat. Their muscle tissue pushes up their weight. Kahan points to very muscular people, like football players or body builders. “Their BMI shows up pretty high, and yet their body fat is actually pretty low," Kahan says.
Ozempic is typically recommended for individuals who have a BMI of 30 or higher, which falls into the obese category, or for those with a BMI of 27 or higher who have additional health concerns such as high blood pressure, type 2 diabetes, or high cholesterol.
At 22% body fat, men often have a softer midsection, less muscle definition, and a healthy but not overly lean look, while women typically appear athletic and toned, with some ab definition visible when flexing and definition in arms and legs, sitting in the "fitness" or "average" range for both genders, though visual appearance varies by individual.