Doctors and dietitians have been relying on the BMI or â€˜body mass indexâ€™, for two centuries. It is one of the key vital signs when assessing a patientâ€™s health. There are new suggestions that the BMI may not be the most accurate measure, however. It may even be that 50% of females are judged to be â€˜healthyâ€™ according to their BMI, but in truth are actually obese. While 20% of males are also incorrectly assessed.
The latest American study measures the percentage of body fat in relation to lean muscle, and this gives a more accurate diagnosis of obesity as well as being a more reliable predictor of associated health risks. Yes, body fat predicts better than BMI. The body-fat measurement process uses dual energy Xray absorptiometry or DEXA for short. It is relatively expensive but gives an accurate calculation of a patientâ€™s obesity status based on fat make-up standards, as used by the American Society of Bariatric Physicians.
Does BMI Accurately Measure Body Fat?
The outcomes of this study and method suggest that BMI is a pretty variable measure of the male fat status. Unlike the case of females however, BMI does not understate obesity in all cases. 20% of males in the study had to be re-categorized from â€˜normal/healthyâ€™ status to be obese. This was 50% in females and a lot more common in males than females also, was the re-categorization from obese (BMI measured) to healthy (DXA measured).
This is the good news in this study for men, but it is only a silver lining on a very black obesity cloud, nationwide. The studyâ€™s authors concluded that “We may be much further behind than we thought, in addressing the nation’s crisis of obesity.”
The report went on to characterize BMI as the â€˜baloneyâ€™ mass index. The general consensus and acceptance of BMI is contributing greatly to the failure of public health policy aimed at reducing American obesity. The study was of almost 1400 patients in private medical care in New York. All attempts to help patients slim down have yielded short-term improvements but long-term weight regains.
The lessons of the report are that better results from medical interventions are achievable if we change the focus to body-fat make-up and away from overall weight. Doctors must also look forward to encouraging lean muscle mass through exercise regimes rather than myopically pushing lifestyle and diet, in particular.
[box type=”important”]Obese people need to be prescribed exercise and educated in ways to modify their body-fat make-up toward lean muscle mass with aerobics, better rest and healthier eating of â€˜realâ€™ (as opposed to highly processed) food, made up of mostly plants.[/box]
This report is not good news for the federal administration on three counts:
- The DXA measurement is more expensive than BMI
- The current obesity epidemic is seriously understated, as is the public health response, and 3) where, in these times of budget deficits and austerity measures can government find the money to make the kind of public health changes needed in the wake of this