Dr. Lopez-Jimenez says bogus BMI has nothing to do with fat
Hey, check this out! In light of our lively discussion the other day about using body mass index (BMI) to determine if someone is overweight or obese, along come this story from Forbes about new research confirming something that many of us already knew in our heart of hearts--BMI IS BUNK!
Lead researcher Dr. Francisco Lopez-Jimenez, from the cardiovascular division of the Mayo Clinic, had been noticing more and more how irrelevant using BMI as a way to measure a person's cardiovascular risk has become because of the indistinguishable difference it makes between body weight and fat weight.
As I blogged about the other day, perfectly healthy people, including myself, are considered overweight or even obese because their weight and height dictate a certain BMI number. Anything 25 and above has traditionally been considered unhealthy and doctors have used that as the impetus to put some people on weight loss regimens to ostensibly lower their risk for having a heart attack or stroke.
Dr. Lopez-Jimenez says his research into 40 different studies of over a quarter million patients found that those with the lowest BMIs, generally under 20, were actually found to have a HIGHER mortality rate as a result of heart disease than those with the so-called dangerously obese levels of 30 and above. How ironic is that?
The researchers say that BMI becomes an even worse measurement as people age because they lose muscle while gaining fat. However, BMI does not distinguish between fat mass and fat-free mass, such as muscle.
Their conclusion: "BMI is a poor measure of body fat."
As that great philosopher Gomer Pyle used to say, "SURPRISE, SURPRISE!"
While this theory about BMI has been bantered about for many years, Dr. Lopez-Jimenez said the medical publishing establishment put up "resistance" about allowing it to be publicized because they wanted more proof it was not the great solution that it has always been thought to be. What Einsteins thought that was the smart thing to do? I'm all for making sure of something verifiably before coming to a conclusion, but this one seemed pretty cut and dry.
Several months ago, Dr. Lopez-Jimenez presented that "extra" evidence to the American Heart Association in a report at their annual meeting which correlated with this previous study that BMI should be replaced with the waist-to-hip ration instead because it is "a better way to distinguish between fat and muscle.
Although he had sharp criticism for BMI overall, Dr. Lopez-Jimenez said it is still an excellent tool for people who are morbidly obese.
"Patients with BMIs of 35 to 40 naively believe that they have a lot of muscle," he surmised. "In [these kinds of] extreme cases, fat determines the measurement."
What?! When I weighed 410 pounds and my BMI was off the charts, I never thought I had a lot of muscle. The only muscle I had was that big 62-inch tumor growing out the front side of my body and it was showing no sign of ever getting smaller. I didn't need BMI, waist-to-hip ratio, or a scale to tell me what was painfully obvious to everyone around me--I WAS FAT!
But as my weight has come down substantially in the past couple of years, so has my BMI. But it is still higher than what has been described as "normal." Even still, my body fat was measured at 11 percent late last year and I look and feel healthier than ever before!
With BMI moving out of the way and these other indicators moving to the forefront of determining health risks, will we turn to body fat percentage as the measuring stick to replace those archaic BMI numbers? The better question is SHOULD WE? What do you think? If not BMI, then how should we track whether someone is at risk for cardiovascular disease?
Additionally, what does this say about the usual dietary recommendations that have been made by doctors for decades? Studies have shown that the cherished low-fat diet has actually INCREASED fat in the abdomen. EEEEK! Meanwhile people who are livin' la vida low-carb are burning lots of fat and getting healthy in the process.
Tell BMI bye-bye and don't ask why! :D