Tag Archive for: obese

BRI: It Just Doesn’t Matter

/in /by

Continuing our look at the BRI, the mathematician demonstrated that BRI is associated with body fat distribution. It makes sense; the waist measurement would provide an indication of fat around the waist. The next question is: would the BRI be a better predictor for cardiometabolic disorders than BMI?

BRI and Mortality

A group of researchers decided to use open-source data from the National Health and Nutrition Examination Survey database to examine the relationship between BRI and all-cause mortality. They coincided with the years that physical assessments were done including height and waist circumference; body weight was collected but not used in this instance. The time period began in 1999 and continued every two years through 2018.

There were two observations that were significant. First, in every demographic group, regardless of age, gender, or race/ethnicity, the BRI has increased during every examination period. As a country, the U.S. has gotten fatter. That matches every other measure such as body weight or BMI as well.

The second observation was that the hazard ratio (HR) increased as the BRI dropped below normal, then normalized when the normal BRI was reached, and the HR rose again as the BRI increased. Simply stated, there was an increased risk of mortality when people were too lean or too fat.

You may be wondering why I don’t give you a formula to do calculations for yourself. It’s very complicated and there are BRI calculators available on the website below. The main reason is that it just doesn’t matter—the BRI is no better at predicting mortality than the BMI. The researchers had the body weight data they needed to compare the BRI with the BMI directly. They just didn’t do it. However, looking at the mathematicians’ validation study, the categories of adiposity associated with BMI matches up quite well with the BRI and thus with body fatness. There’s no need for any more precision than is achieved with BMI.

The Bottom Line

It’s really the clinical use that seems to bother everyone, but with rare exceptions, the BMI gives an indication of body fatness. If physicians or other health care professionals cannot see the patient before them and realize they are too lean or too muscular to fit the typical interpretation of BMI, the fault lies with them, not the tool they are using.   

What are you prepared to do today?

        Dr. Chet

References:
1. JAMA. 2024; 332(16):1317-1318. 10.1001/jama.2024.20115
2. JAMA Netw Open. 2024; 7(6):e2415051. 10.1001/jamanetworkopen.2024.15051.
3. https://doi.org/10.1002/oby.20408
4. https://bri-calculator.com/#calculator

Body Roundness Index

/in /by

The Body Mass Index (BMI) has been used to provide an indication of whether someone is under weight, normal weight, overweight, or obese and the degree to which they are obese. There’s no measure of percentage of body fatness implied, but physicians and other medical professionals have used it for that purpose for a couple of decades. Why? It can be used to assess the potential risk of developing cardiovascular disease, pre-diabetes, and other metabolic conditions.

I happened upon a commentary in JAMA on the Body Roundness Index or BRI for short. It was published in response to a recent study published in a JAMA Network Open by researchers who examined the relationship between BRI and mortality.

Let’s start with this: what is the BRI? The BRI was developed by a mathematician. The reason was interesting; the developer told the commentator that the BMI is based on a “cylindrical” model but when she looked in the mirror, she felt she was more egg shaped. What she did, as a mathematician, was develop a model based on an “ellipse.” Why? She gave a couple of reasons.

The first reason is that BMI can misclassify individuals because it fails to distinguish between individual amounts of fat-free mass (FFM) and fat mass (FM). BMI also does not provide information about the distribution of body fat—specifically, visceral fat versus subcutaneous fat. She developed a mathematical model, to assess body fatness which would indicate where the fat is distributed. With some very complicated math, she developed the BRI. It uses only two measurements: height and waist circumference. The benefit of using the BRI is that it may be a better predictor of body fat than the BMI. Is it? We’ll check out the research study that began this examination of BRI on Saturday, because as Shaq famously said about getting in shape, “Round is a shape.”

The Insider Conference Call is tomorrow night. If you become an Insider by 8 p.m., you can participate in the call to get your questions answered.

What are you prepared to do today?

        Dr. Chet

References:
1. JAMA. 2024; 332(16):1317-1318. 10.1001/jama.2024.20115
2. JAMA Netw Open. 2024; 7(6):e2415051. 10.1001/jamanetworkopen.2024.15051.
3. https://doi.org/10.1002/oby.20408

Metabolically Healthy and Obese

/in /by

The researchers in Germany continued to determine which factors associated with being obese were the most predictive of mortality from any cause and from cardiovascular disease. While not explicitly stated, it seems to me that they attempted to use variables that were simple to assess. With that in mind, here are the variables which demonstrated whether someone was metabolically healthy or not, regardless if they were normal weight, overweight, or obese.

Criteria for Metabolic Health

  • Systolic blood pressure less than 130 and no use of blood pressure lowering medication
  • Waist-hip ratio less than 0.95 for women and less than 1.03 for men
  • No prevalent diabetes

These criteria are simple enough for most people to determine for themselves, no doctors necessary. People usually know whether they’re diabetic, and they also know whether they’re taking medication to lower their blood pressure. Most people have a home BP cuff to assess systolic blood pressure or have access to one in a store.

The waist should be measured at its widest point and hip should be measured at the bony process of the femur. Divide the second number into the first, and that gives you the waist hip ratio.

The Results

The subjects who were considered metabolically healthy and obese had no greater risk of mortality from all causes or from cardiovascular disease then did normal weight, metabolically healthy subjects. This study examined only the death rate, not the rate of disease. Still, I think that if someone is working towards becoming a healthier version of themselves, intermediate goals can be very motivating.

I like this study for two reasons. First, it confirms what I thought for many years: people who are overweight or obese can be metabolically healthy. Second, it means that instead of trying to lose all the weight a person needs to lose, there can be intermediate steps on the way to becoming the best version of yourself; in fact, you don’t even need to be trying to lose weight to start being healthier.

The study also found that some people who were metabolically unhealthy and normal weight or slightly overweight were at higher risk for cardiovascular disease and total mortality. Could it be that the reason for the reduced risk was exercise? It was not considered, but it would be interesting to see further analysis on the data to determine if fitness was a contributing factor in metabolic health.

The Bottom Line

This study provides a basis for assessing risk of mortality on more than just BMI. What it shows is that even though you may be carrying too much weight, that doesn’t mean that you’re automatically at risk for death due to cardiovascular disease or other causes. I believe regular exercise is critical to achieve metabolic health and thus reduce your mortality risk, so that’s your first step to becoming and staying metabolically healthy.

What are you prepared to do today?

        Dr. Chet

Reference: JAMA Net Open. doi:10.1001/jamanetworkopen.2021.8505

Can You Be Obese and Healthy?

/in /by

The research question that was most interesting to me as a graduate student was this: could you be overweight, even obese, and still be healthy? That question still interests me today, and for good reason: 70% of the U.S. population is overweight or obese, and we’ve just passed 40% of the entire population falling into the obese category. And it’s not just the U.S.; we’ve exported our poor fitness and diet habits around the world.

Research done decades ago from by Cooper Institute, most often under the direction of Steven Blair, demonstrated that you could be fat and fit. Their research showed that people who were obese, meaning they had a BMI greater than or equal to 30.0, were no more at risk for death from cardiovascular disease or all-cause mortality if they were in the high fitness category.

That’s not the same question as this: could you be metabolically healthy and at no more risk for death from cardiovascular disease or all-cause mortality than someone with a normal BMI (18.5-24.9 kg/m2)? Researchers from Germany decided to examine that question. They used data collected from the National Health and Nutrition Education Survey III, which included over 12,000 subjects, and the U.K. Biobank, which contained over 374,000 subjects. Then they examined the statistical relationship between many different variables such as triglycerides, total cholesterol, hemoglobin A1C, C-reactive protein, systolic blood pressure, and on and on. Once they had a series of statistical relationships between obesity and mortality, then they sought to derive as simple an algorithm as they could to develop a profile of someone who would be metabolically healthy and obese. I’ll tell you more about that in Saturday’s memo.

Meanwhile, have you examined that map that was part of the CDC atrial fibrillation primer? Here’s what I saw: I’ll call it the I-75 Corridor of A-fib. Starting in Flint, MI, if you follow the pattern of the deepest red, it follows I-75 through Detroit to Toledo, OH, then Cincinnati, OH, and all the way down through Georgia to Florida. That’s the I-75 Corridor of A-Fib. What does it mean? Nothing, as far as I know; it doesn’t correspond to race or income or temperature. It’s an observation, nothing more, but maybe some epidemiologist or statistician somewhere will look into in more deeply.

What are you prepared to do today?

        Dr. Chet

Reference: JAMA Net Open. doi:10.1001/jamanetworkopen.2021.8505

Triathlon Observations: Prepare to Compete

/in /by

Let me be clear: I think that the single most important thing that you can do to be healthy is to exercise regularly. Whether walking, swimming, or one of the hundreds of other types of exercise, talking with your physician about it may be all that’s required for you to get started.

Moving from exercise that helps your health to competing in fitness events requires more—that’s independent of your body weight lest you think I’m talking only about the very heavy people that competed in the triathlon. Here’s what I recommend.

First, you should have a stress test that assesses how your heart and blood vessels perform under maximal conditions. That applies to men over 40 and women over 50, for sure. But I also think if you have been overweight for over five years, you should have the test regardless of age. The maximal exercise test is not foolproof, but it’s the best available predictor of heart problems. This isn’t just me being a worrier; I’m sad to report that one participant died of a heart attack last Sunday. Getting checked out before you start is the best way to protect yourself.

Second, you should have a complete lipid profile, HbA1c, and a blood insulin test as a minimum. As I suggested in Thursday’s memo, you need to know whether you’re a prediabetic or even an undiagnosed type 2 diabetic. The best option for you would be to exercise, but when you push yourself hard for long periods of time, it’s going to affect your blood sugar levels as it would affect a diabetic’s, not someone who has a normal carbohydrate metabolism; for instance, you could pass out if your blood sugar gets too low, and if you’re out alone on a run, that’s a problem. You can deal with it, but you have to know if it’s an issue.

Third, you should get an orthopedic analysis. By that I mean that your joints should be evaluated for range of motion, tendon and ligament stability, and gait. Swimming affects the shoulders, bicycling the lower back, and running the hips, knees, and feet. Any abnormality will be exacerbated; for example, the forces you create when you run is five times your body weight. Do the math—that’s a lot of stress on your knees and feet.

Once you get the all clear, get after it. Start conservatively but if you have the urge to compete to see what you’re capable of, do it. I think if you want a challenge, whether to walk or run a 5K, swim a mile, or bike 50 miles, or combine them into a single event such as the triathlon, you should do it. Just make sure you get your body checked out before you do.

Final Observation

While I believe exercise is important no matter the level at which you do it, exercise won’t help you lose a lot of weight. Surprised? Remember the size of the people I mentioned that competed in the triathlon—not just overweight but obese? If they had put in the training, and I know some of the competitors and know that they did, you’d have thought they would have lost a significant amount of weight. They didn’t.

Burning calories helps with weight loss, but as a well-known expert once said “Americans can’t out run their appetites.” If you could exercise six or eight hours a day, you could probably lose weight without changing your diet, but I doubt you have that kind of time. You can use exercise as a tool to help you lose weight, and exercise pays major benefits in fitness, strength, and stamina. But you will not lose weight unless you also eat less and eat better.

What are you prepared to do today?

Dr. Chet

 

Triathlon Observations: Heavy and Healthy?

/in /by

The major observation I had as I volunteered at the Grand Rapids Triathlon was that the body weight distribution of the people participating in the triathlon mimicked the population of the U.S. We’re a fat nation; 70% of the population is overweight and half of those are obese. Those percentages also seemed to apply to the participants in the race.

In addition to being a regular Grand Rapids event, the Grand Rapids Triathlon was also the National Championship for the Clydesdale and Athena athletes. In order to qualify for the Clydesdale division, men must weigh over 220 pounds; for women to qualify for the Athena division, they must weigh over 165 pounds. Based on my observations, a majority of the participants would have qualified for that category, whether that was their intention or not.

There were men well over 300 pounds and women over 250 pounds that participated in the triathlon. Talking with several other volunteers, I said that unless they had a signed release from their physician, I would hesitate to let them participate. They countered that as long as people put in their time training, they were fit enough to compete. Good point, but that logic doesn’t really hold up. The primary concern everyone thinks of is cardiovascular disease and that makes sense. But if someone is overweight, the real concern is undiagnosed type 2 diabetes and orthopedic stress.

While I applaud their effort and would never want to prevent anyone from exercising, I would hope that they would have had a thorough medical exam before they took their first step. We can’t assume because they had trained for the race they were actually healthy enough to compete in the race. I’ll cover what those tests should be and a surprise conclusion that you don’t want to miss on Saturday.

What are you prepared to do today?

Dr. Chet