Dr. Tom Refai explains why BMI fails as a health measure: it ignores body composition and fat distribution, misses insulin resistance, and can bias against certain ethnic groups. He recommends DEXA scans and fasting insulin tests instead, noting BMI only works reliably at extreme values.
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All right, everyone. Is BMI racist? Well, this has come into the news recently due to an AMA declaration that we should de emphasize the use of the body mass index which only looks at height and weight. And I haven't been a fan of for many, many, many, many years and has evolved into calls that the BMI measurement is racist. Well, let me just make it simple and easy for you. Never believe that BMI was a great tool in individuals body mass index, which looks at only height and weight, basically your weight in kilograms divided by your height in meters squared. Not unreasonable tool for large populations, hundreds or more, even so thousands of people. Now you call people up, how tall are you? How much do you weigh? How tall you. How much do you weigh? How tall are you? How much do you weigh? They mostly tell us that they're taller than they really are and weigh less than they really do. It's not a bad tool for a large population because the issue at play, which is really a fat to body, body fat to muscle ratio, excuse me, is the issue. And in fact we could argue it's actually the quality of muscle too, not just the quantity. And then where is the fat at? How is it distributed? Are you more of an apple, centrally gathering body fat in your abdomen like someone like me or some populations we'll discuss that in general tend to gather body fat more preferentially in their abdomen, even without much weight gain. They can really get into serious trouble. Or are you more of a pear or an avocado, I guess, if you will, where body fat is stored more peripherally in the hips and thighs, for instance, where it'd be less metabolically risky, if you will, than if it was gathered around your internal organs or vaginal viscera, so called visceral fat. So I haven't been a fan of body mass index for many years and then practiced using DEXA body composition analyses. DEXA is the scanner that is most often known for bone density scanning, but it is also a gold standard for body composition analysis. It's different software program, but it's the same scanner, it's the same very low radiation risk and it is the most accurate. Actually it's the second most accurate way of testing body composition, but the most accurate is cremation. So let's, let's avoid that. Bottom line is that the body mass index does show some ethnic or ethnocentric, if you will, but ethnic bias in the sense that in populations, everyone being an individual, and you never know until you sit down with someone specifically. But in certain populations we Know that fat is gained preferentially in the abdomen. Asian populations, whether India, Pakistan, China, Japan versus populations, let's say for instance African American women or basically those with ethnic ancestral roots to Africa women that have a more pair tendency that that body fat is gained less risky fashion when there's excess calories and therefore would be biased against with a BMI measurement because if they hit a BMI of borderline obesity they would be called oh you're almost obese or let's say they're in the obesity category and yet their risk of insulin resistance as a population would be significantly less at a given BMI than an Asian population, for instance. Instance. So in either direction, you know, you could see that there's ethnic bias, not necessarily intentional, but by the weakness of the calculation itself. Its strength being that it's simple also is a double edged sword. Its weakness in that it's not particularly accurate or precise for determining metabolic health risk. It's not nothing you like that double negative. Sorry English teachers, but it is certainly not something in which we should over rely on. You really want to look at someone's metabolic health, for instance and their risk of diabetes. I would be looking at something like fasting insulin. So if you look at a fasting insulin level using the US units, if you have a fasting blood sugar that's normal, let's say it's 92 with less than 100 being considered normal. And then you look at these are using US units by the way, you'd have to divide by 18 to get international units. If you want to take that 92 and turn it into your international units Melamoles per liter. But I'm going to stick to US units and their calculators out there. So by all means everyone just switch using a calculator to keep it simple. Most of the audience here probably from the US let's say your blood sugar is under 100 and let's say it's 92. Again one person's fasting insulin associated with that 92 is 14 or 24 or 34. But bottom line is it's deeply into the double digits versus someone else's blood sugar of 92 with a fasting insulin of only 4 or 3. That that combination of an optimal fasting glucose less than 100 with an truly what I would consider optimal versus normal in the context of a United States where we have over 90 million people who are who have prediabetes and most of which are unaware that is the ideal fasting glucose less than 100 concomitant with a fasting insulin less than 5 if you have a fasting glucose under 100, again, let's say 92, but your fasting insulin is not 4, but rather 14 or 24 or 34. These are two totally different blood sugar assessments. Actually, I would say insulin sensitivity assessments because you're combining the glucose with the fasting insulin. In the latter case, where the fasting insulin is high, you know that pancreas and that beautiful person that you're working with is working hard to maintain a normal blood sugar. And of course, the question is not only how much longer can the pancreas keep sprinting a marathon and eventually burn out? And then, then you have pre diabetes, which is the tip of the iceberg. The insulin resistance could have been detected years back. But all of the other things associated with insulin resistance, whether it be hypertension, cardiovascular disease, and other manifestations of cardiometabolic disease, including insulin sensitive cancers such as breast cancer, colon cancer, dementia. And then you can imagine if we're just looking at blood glucose rather than BMI or just height and weight and we're having to dig even deeper with fasting insulin. How imprecise in an individual is BMI for detecting health risk? Now, clearly, when BMI is in the extreme ranges, okay, let's say it's less than 18, where we are obviously concerned about bone health, anorexia nervosa, for instance, or the body mass index is 40 or higher, which would be considered severe. We're gonna use the word morbid. Okay, don't, don't use the word morbid. Obesity professionals that are watching this, you know, the preventive death risk of smoking is still higher than or at least equal to at best, so called morbid obesity. But we don't call people morbid smokers. Okay, That's a judgmental term in a way that's not helpful. But we can use the term severe. Okay, beyond body mass index of 40 or higher is severe obesity. That of course is reasonable, but at that level, wouldn't you be looking deeper than BMI anyway, whether it's BMI lower than 18 or above 40. So there you go. That's the bottom line from Dr. Tom Refai. Over 20,000 hours of clinical experience and intensive lifestyle intervention, past president of the National Board of Physician Nutrition Specialists and MASS Regional Metabolic Health and Weight Management Director for Henry Ford Health. And I will put my bio for further detail into my background, which also includes one of binge eating disorder, which I almost lost my life and unfortunately lost my youngest brother, Basil May God rest his soul life to binge eating disorder. So I see things from not just a professional, but a very personal perspective. If you like that type of content from an expert like myself that mixes professional and personal experience, by all means, please like this video, subscribe to the channel, click the notification bell and share as widely as you like and we'll see you here next time. And I hope to give you some deeper insights, but not so that it's too complicated, helping you find where reality meets science when it relates to health and your well being. Bye bye.
