We know that anyone with a BMI (body mass index) of 30 and over is considered obese but it could now seem that levels of obesity in the United States could actually be higher than earlier thought. Researchpublished in the journal PLoS One has suggested that 39% people who are not currently regarded as obese may actually be obese.
Americans could be fatter than earlier thought
Current figures from the CDC (Center for disease control) say that one in three Americans is obese, but estimates say that the situation could actually be a lot worse.
The charge is that there are shortcomings in theBMI methodology of measuring obesity. BMI is insensitive and is prone to under diagnosis says Dr Eric Braverman, one of the researchers who were part of the study.
Direct measurement of body fat percentages is a more accurate and a better way of measuring obesity.
When researchers examined the medical records of 1393 people, a very significant percentage were not labeled as obese when in fact they should have been if their body fat percentage was taken into account.
The BMI classification becomes particularly inaccurate in older women, found researchers. This is because older women tend to lose a lot of muscle mass and this adds to the problem.
Other problems with BMI
Earlier as well, there have been problems suggested with obesity calculations based on BMI. By BMI estimates, a lot of athletes with high percentages of muscle in their bodies could also be classified asoverweight or obese, though they would otherwise have very low body fat.
There is also the fact that BMI cannot gauge fat distribution and hence cannot predict disease risk. Those people with higher fat deposits around the waist are known to be at higher risk of high blood pressure, diabetes and heart disease. However, BMI cannot distinguish between types of fat distribution and hence cannot predict disease risk.
BMI classifications are also inaccurate for certain ethnicities, it is suggested and that the waist-to-height ratio (WhtR) may be a more reliable indicator. Asians tend to carry more weight around their middle and so their disease risk may be higher even at lower BMIs.
The worry is that mere BMI screening could miss people’s real disease risk – by underestimating the risk of apple shaped individuals who may seem of a normal weight as well as by over assessing the disease risk of seemingly overweight pear shaped individuals.