Times Change, Our Bodies Change, And Now The Body Mass Index (BMI) Guidelines May Change Too

A recent news story in the Journal of the American Medical Association (JAMA) reminds me that lots of things in our lives are changing these days, not the least of which is the shape of our bodies.

Oh, my. This aging thing isn’t so easy, and that is really the message behind Rita Rubin’s timely piece about shifting body mass and muscle as we age and its implications. Although focused on women, I can attest personally that men fall into the same trap as well. That 250 pounds when you are older simply is not the same 250 pounds when you were in college. Now 250 pounds looks more like 280—even though the scale still says 250. Go figure…

Although I may be trying to provide a little humor to the subject, the reality is it’s not humorous when it comes to our health. As we age, muscle turns to fat. In a process called “sarcopenia,” muscle begins an inexorable march to become fat, and for most of us it doesn’t make too much difference how much we try to forestall the shift. It is programmed into our bodies, and although exercise might help, Mother Nature simply doesn’t care as much about the gym and the treadmill as she used to.

There are practical implications to this process, as pointed out in the JAMA article.

Much of our routine health is predicated on maintaining a healthy weight. The most frequent measure of whether we are classified as “healthy”, overweight, or obese depends is body mass index (better known as “BMI”) which is calculated by measuring height relative to weight. It is not a perfect tool, however for general populations purposes it is the best tool we have.

Yes, there are exceptions. The classic example is Sylvester Stallone (among others), who had a very high BMI at his peak, however was obviously not overweight or obese. I can’t tell you how many times I have heard that excuse from someone who was obviously a bit on the paunchy side: “Oh, that’s not fat. It’s muscle!!! After all, I work out every day!!!”  (I learned as a physician to wonder whether those workouts were in the gym or walking multiple times back and forth to the fridge. However, I digress.)

What most of us probably don’t know is that BMI definitions have not always been what they are today, where 25 defines “normal” from abnormal. That line of demarcation used to be higher, however it was reduced, and in the process shifted a lot of folks from healthy to overweight. So the target numbers are somewhat arbitrary, hopefully backed by good population science that defines the difference —pardon the pun—based on solid scientific information.

As pointed out in the article, there is now debate once again whether the BMI numbers should be changed for post-menopausal women.

It appears that too many women who have either a “healthy” BMI or a slightly overweight BMI in fact are not healthy and have too much body fat as measured by more accurate techniques. If that’s the case, then an adjustment for these women might be appropriate to better define a weight relative to height that would more accurately reflect true “health.”

In other words, just because you think you are healthy doesn’t mean you are healthy. And it is possible that if the mavens of weight decide to change the BMI definitions, we could suddenly have a whole lot of folks who thought they were healthy and maintaining that proverbial “healthy body weight” suddenly facing the fact that they are not as healthy as they thought they were.

As if we didn’t already have enough things to worry about, now we have to get back on the diet and the scale. Does it ever end?

Lest you think I don’t take this matter seriously, I can speak from personal experience that weight has been one of the most persistent issues that has dogged me throughout my lifetime. And try as I might, I couldn’t reverse the inexorable reality that I observed in myself: I weighed the same as I did in college, I work out much more than I did in college, however my body kept going in the wrong direction. Even my precious granddaughter blurted out one day recently that my belly had reached, uh, a larger size.

And, yes, even with all the exercise I am still trying to find out what my weight is going to be, and what I must achieve to reshape this torso into something more presentable. Today my weight is down 30 pounds—again—and I still have a long way to go. And if they change that BMI thing, well I will be eating cardboard for a very long time.

Kidding aside, this is a genuine issue for many of us. We want to be healthy, we want to be mobile, we would really like to reduce our blood sugar, cholesterol and blood pressure while reducing our risk of disease and even cancer. It’s not easy, as we all know. Many of us have been there time and again. And if that BMI thing moves further down the scale, it will capture many of us in its clutches, seeming to never let us go.

However, science is science, and data is data—as difficult as it may be to confront our reality. But confront reality we must if we are to make progress as a nation when it comes to our health. Right now unfortunately when it comes to body mass this country for the most part is headed in the wrong direction. Perhaps this type of discussion will help more of us focus on something that is in fact very important to our wellbeing: namely, our weight.

Yes, times are changing. And our bodies are changing. What is important to remember for our health is what we do about it. Maybe it’s time we change along with the times



J. Leonard Lichtenfeld's Biography

Dr. Len

J. Leonard Lichtenfeld, MD, MACP: Dr. Lichtenfeld currently serves as Deputy Chief Medical Officer for the American Cancer Society in the Society's Office of the Chief Medical Officer located at the Society's Corporate Center in Atlanta. Dr. Lichtenfeld joined the Society in 2001 as a medical editor, and in 2002 assumed responsibility for managing the Society's then newly created Cancer Control Science Department which included the prevention and early detection of cancer, emerging cancer science and trends, health equity, quality of life for cancer patients, the science of cancer communications and the role of nutrition and physical activity in cancer prevention and cancer care.  In 2014, Dr. Lichtenfeld assumed his current role in the Office of the Chief Medical Officer where he provides extensive support to a number of Society colleagues and activities. As a result of his over four decades of experience in cancer care, Dr. Lichtenfeld is frequently quoted in the print and electronic media regarding the Society's positions on a number of important issues related to cancer. He has testified regularly in legislative and regulatory hearings, and participated on numerous panels regarding cancer care, research, advocacy and related topics. He has served on a number of advisory committees and boards for organizations that collaborate with the Society to reduce the burden of cancer nationally and worldwide. He is well known for his blog (www.cancer.org/drlen) which first appeared in 2005 and which continues to address many topics related to cancer research and treatment. A board certified medical oncologist and internist who was a practicing physician for over 19 years, Dr. Lichtenfeld has long been engaged in health care policy on a local, state, and national level.  He is active in several state and national medical organizations and has a long-standing interest in professional legislative and regulatory issues related to health care including physician payment, medical care delivery systems, and health information technology. Dr. Lichtenfeld is a graduate of the University of Pennsylvania and Hahnemann Medical College (now Drexel University College of Medicine) in Philadelphia.  His postgraduate training was at Temple University Hospital in Philadelphia, Johns Hopkins University School of Medicine and the National Cancer Institute in Baltimore. He is a member of Alpha Omega Alpha, the national honor medical society.  Dr. Lichtenfeld has received several awards in recognition of his efforts on behalf of his colleagues and his professional activities.  He has been designated a Master of the American College of Physicians in acknowledgement of his contributions to internal medicine.  Dr. Lichtenfeld is married, and resides in Atlanta and Thomasville, Georgia.

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