Tag Archive for: BMI

Metabolically Healthy and Obese

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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?

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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

COVID-19 and Obesity

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Obesity may be a contributing factor to the severity of symptoms for those who get COVID-19. The best explanation I’ve found why that may be true is in a paper in Nature Reviews Endocrinology published in April. There are several reasons in addition to the cardiovascular and endocrinological co-morbidities associated with obesity.

Just a reminder, by definition obesity is a Body Mass Index (BMI) greater than or equal to 30.0 kg/meters squared; it’s a measure of surface area. You can check yours at the Health Info page on the Dr. Chet website; it also includes the info to determine if you’re really big boned, because that has an impact.

The increased risks associated with obesity are driven by the respiratory system:

  • Impaired respiratory mechanisms
  • Increased airway resistance
  • Impaired gas exchange
  • Low lung volume
  • Low muscle strength

In effect, the greater the obesity, the more difficult it is to breathe deeply and when deep breaths are taken, the resistance within the airway and the actual exchange of oxygen and carbon dioxide are impaired. If required, intubation is more difficult. The greater the degree of obesity, the more difficult it is to provide regular patient care if someone is hospitalized with the virus. Add to all that the co-morbidities of the cardiovascular and endocrinological systems, and it makes recovery very difficult. More research is needed, but it’s a serious issue in a country where over 40% of all adults are obese.

I’ll wrap this up on Saturday with some thoughts about what we don’t know that could be impacting the development of treatments for the COVID-19 virus.

Facebook Messenger

I try to make myself as accessible as possible, and Insiders and Members have quicker access. My website contains a way to email me if you have a question. One way I’m no longer going to accept questions is via Facebook Messenger, so please use one of the other avenues.

What are you prepared to do today?

        Dr. Chet

Reference: Nature Reviews Endocrinology volume 16, pages341–342. (2020)

What’s Your Body Mass Index?

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You may be tempted to measure how you’re doing on the way to your health goals with body composition read-outs on scales and other outputs related to body fat analytics, but how accurate are they? If the device used is one that has you stand on a scale or hang on to handles of some sort, the accuracy of those numbers is very limited.

Those devices are based on impedance technology—the resistance of a very small current passed through your body. It actually can be very accurate when it comes to total body water, something very important for people with congestive heart failure. Everything else is based on algorithms that assume specific characteristics of the body. Those may be valid assumptions, but the variability is too great person to person. How do I know that? I worked on the impedance device as a grad student, so I know it well.

If you really want to track how you’re doing related to fatness, use the Body Mass Index. Every health insurance company uses that as a metric to assess your fatness.

“But I have bigger bones!” you say. Or maybe the weight recommended for you seems too high. In fact you may have a larger or smaller frame than average, and I explain how to know for sure with an easy measurement in the Health Info section titled Body Mass Index. Check it out today for an in-depth look at BMI.

What are you prepared to do today?

        Dr. Chet

Life Expectancy Is More Than Living Longer

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What’s more important to you: living longer or living better with the years you have? Think about it as you read this Memo and I’ll come back to that later.

The Upside of the Study

There were three important lifestyle variables that clearly stood out (1). The more exercise you get, the better off you are. Of those who got perfect 5s, they averaged over an hour per day of exercise. Second, the lower the BMI, the better; researchers didn’t track who might have lost weight over the years to get in the lowest BMI category, but it’s clear that carrying fewer pounds helps.

Finally, the Alternate Healthy Eating Index (AHEI) is a score of the quality of the diet, not the quantity. The highest quintile was below 60 out of 100 possible points. That means you don’t have to eat perfectly; just eat your vegetables and fruit and fewer refined carbohydrates and sugars, and you’ll see benefits.

The Downside of the Study

The subjects were overwhelmingly white and they were nurses and doctors for the most part. Whether that translates to other races and professions, we just don’t know.

The biggest issue for me is the Food Frequency Questionnaire used in the original studies as well as the AHEI scores. Trying to remember what you’ve eaten in so many categories over a year never made sense to me; there’s just too much potential for error. There were also differences in AHEI scores between the Nurses Study (all women) and the Health Professionals Follow-Up Study (all men). The men had an AHEI of 59 while the women in the nurses study had an AHEI of 37.5 in the groups assigned a 5. That makes no sense to me. I know the FFQ were slightly different, but the way the data are extracted to arrive at the AHEI score should have accounted for that. Are men so much better with the quality of their diet? Not buying it.

Supplements

Here’s something I found interesting. The use of a baby aspirin went up as the overall scores went up. In contrast, multivitamin use went up as the overall scores went down. To me, that means that healthcare professionals in all professions know that taking a baby aspirin is good for you. It also means that the poorer the diet, the more people try to compensate with supplements. The goal should be to complement a good diet with a multi, not try to make up for a poor one.

Amount of Time Living with Disease

I asked you a question at the beginning of this memo: what’s more important to you: living longer or living better? Right now, the average number of years spent living with some form of disease is almost 12 years (2). Not every condition is as debilitating as others, but would you rather live longer no matter what your health is or would you rather live well right up to the day you check out? Only you can answer that one. The study didn’t examine quality of life so we don’t know how the subjects did.

Here’s my guess: I would wager that the more healthy lifestyle variables you can add to your life, the longer and better you will live. Eat less. Eat better. Move more. It all starts with those six words.

What are you prepared to do today?

Dr. Chet

 

References:
1. https://doi.org/10.1161/CIRCULATIONAHA.117.032047.
2. https://ourworldindata.org/life-expectancy.

 

The Truth Behind the Obesity Paradox

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In my opinion, the short answer to the obesity paradox is that it doesn’t really exist. But what fun would that be? That doesn’t teach you anything. Let’s take a look at the problems with the research that contributed to this paradox.
 

Study One: Dialysis, BMI, and Mortality

A study of dialysis patients led to the first observation that people with higher BMIs lived longer (1). After tracking over 1,300 subjects on dialysis for a year, researchers found that those who were overweight had a decreased risk of dying and had fewer hospital stays when compared to those who were underweight. This may have been the study that yielded the name The Obesity Paradox. The problem? The study lasted only one year. Trying to generalize what will happen to all overweight and obese people on dialysis from a study that lasted only one year and at only a single location isn’t realistic. It raises an intriguing question, but we’ll need a much more extensive study to really make a solid prediction.
 

Study Two: The Rotterdam Study

I described this study on Thursday (2). While the study appeared to show a protective benefit from being overweight or obese, the subjects were elderly with an average age of 77 at the study’s beginning. One risk factor that you cannot change is age: the older you are, the more likely you are to die. But that’s not the whole story. We can probably say that older people may live longer with a little extra weight, but to extend that prediction to all age groups isn’t valid.
 

Study Three: BMI and Mortality

While this study claimed to analyze the data on over two million people, it was still a meta-analysis (3), which doesn’t yield cause and effect, just a statistical association. Further, they used studies of varying lengths without necessarily knowing exact causes of deaths. They also did not have precise BMIs on everyone; some studies included metrics such as BMI under 27.5 and over 27.5. They tried to include the highest number of subjects, but the quality of data varied and that made it a mess. Researchers chose too many different types of studies in the meta-analysis, and it just doesn’t work. I wouldn’t bet my life on it.
 

Study Four: A Broader Look

The real problem with every approach is the lack of acknowledgement that people with advanced disease may have lost weight before they were included in the study; diseases such as heart failure, diabetes, or renal disease will often lead to weight loss. Those who were heavier when disease hit had the benefit of extra energy stored as fat to deal with the disease, and that could explain the outcomes of those studies. It had nothing to do with being obese; it was a matter of timing.

A study published last month appears to confirm that (4). Researchers in the Cardiovascular Disease Lifetime Risk Pooling Project obtained data from 10 different longitudinal studies, including individual-level data and accurate mortality data. They found that as BMI increased, the death rate from all forms of CVD increased. For those who carried extra weight while younger, CVD occurred earlier, making it more likely they would die before their time.
 

The Bottom Line

As I said, there really is no obesity paradox. Being overweight or obese carries with it risks of degenerative disease. Some people may have better genes and may gain protection for a few years. But in the end, being overweight or obese carries a higher risk of various diseases than the limited protection from an advanced disease you may gain by carrying extra weight. So my advice is the same as it always was: if you’re overweight, your best bet for a long, healthy life is to lose it.

What are you prepared to do today?

Dr. Chet

 

References:
1. Kidney International, Vol. 55 (1999), pp. 1560–1567.
2. European Heart Journal (2001) 22, 1318–1327.
3. JAMA. 2013; 309(1): 71–82.
4. JAMA Cardiol. doi:10.1001/jamacardio.2018.0022.

 

Does a Little Extra Weight Keep You Alive?

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The Rotterdam Study was begun in 1991 to investigate the risk factors of cardiovascular, neurological, ophthalmological, and endocrine diseases in people 55 and older (1). The study is still ongoing, but periodically subsets of subjects are examined to find out which characteristics are associated with these diseases. In a study published in 2001, researchers reported on a group of subjects who were diagnosed with heart failure at the beginning of the study and followed for an average of six years—181 out of over 5,000 subjects. By the end of five years, 85 subjects had died. One of the observations that researchers noted was that a higher BMI was associated with reduced mortality; in plain terms, the heavier people were more likely to stay alive.

It didn’t stop there. In 2013, a study was published that directly examined the relationship between BMI and mortality (2). This meta-analysis included 97 studies and examined more than 2.88 million participants and more than 270,000 deaths. They reported that while grades 2 and 3 obesity (grade 2: BMI of 35-39.9; grade 3: BMI more than 40) were associated with increased mortality, grade 1 (BMI of 30-34.9) was not, and the overweight category (BMI of 25-29.9) actually showed a reduced risk of dying. (How do you rate? Check your BMI here.)

Is this true? Is body weight not associated with an increased risk of death? Have we been trying to lose weight for no reason? I’ll finish this on Saturday.

What are you prepared to do today?

Dr. Chet

 

References:
1. European Heart Journal (2001) 22, 1318–1327.
2. JAMA. 2013 January 2; 309(1): 71–82.

 

What Is the Obesity Paradox?

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Did you ever hear something that didn’t seem to make sense? That seemed to go against everything you thought to be true? One example of this is something called “The Obesity Paradox.” I’ve seen a few headlines this week that have talked about it, so it’s time to address it in the Memo.

One of the variables that we would think is related to the development of cardiovascular disease would be body weight. It seems logical: as weight increases, so does the strain on pumping the blood through the additional blood vessels required to feed the extra fat and muscle. People who are overweight may eat the wrong foods, consume too much food, and move too little.

But since the early 2000s, several studies have been published seeming to show that body weight wasn’t necessarily a risk factor for CVD or an early death. They showed that those who were overweight, a BMI between 25.0 and 29.9, had lower mortality rates than those who were normal weight. Some showed that stage-one obesity, a BMI between 30.0 and 34.9, was also not related to mortality. Thus the term “The Obesity Paradox” was coined. But is it true? We’ll take a look at the research the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Essential Tests: Bones and Body Fat

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After Saturday’s Memo, the logical question is: “How do I really know if I’m overfat?” This weeks Memos are going to be about tests. No, you don’t have to study for these tests. I’m talking about medical tests to talk about with your healthcare provider.

At this point, the best way to test for body fatness is using dual-energy X-ray absorptiometry (DEXA). This process uses low-beam radiation and can identify the three main tissues that make up our body: bone mass, lean mass, and fat mass. Yes, DEXA is the same technology that’s used to determine your bone mass to test for osteopenia and osteoporosis. Instead of just doing the wrist and pelvis, the entire body is scanned to determine body composition.

If you want to know your bone health and your body composition, check out the medical services in your area. There’s one hospital that offers DEXA for both purposes in Grand Rapids. If you’re over 40, it’s a great idea to do both tests. The bone scan will most likely be covered by insurance while you may have to pay for the body composition. The cost is about $100 in this area. If you want the most accurate method for bone mass and body composition, check out the DEXA availability in your area.

The goal is to use this information to improve your health. Reducing body fat and increasing bone mass both end up using a similar strategy: Eat less. Eat better. Move more. On Thursday another simple test that’s too often ignored.

What are you prepared to do today?

Dr. Chet-

 

Normal BMI but Still Too Fat

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Last week the health headlines shouted “Study Shows Over 90% of All Americans Are Overfat!” The rate of overweight as assessed by Body Mass Index (BMI) is already 70%; now scientists want to say even more people are too fat? What’s going on? I’ll explain what overfat means first and then tell you about the study behind it.

For the most part, the greater the BMI, the greater the risk for cardiovascular disease, prediabetes, and hypertension. For those of you who aren’t sure of your BMI, check out your BMI in the Health Info section of our website. And if you think you’re just big boned, we show you how to prove it.

But there are people who have a normal BMI under 25.0 but still may be overfat. Considering Waist Circumference in addition to BMI may help but that could still miss some people. How? They may have lost muscle mass; the subtle loss of lean muscle with a gain of fat could lead to overfatness. That increases their risk for the diseases I mentioned earlier.

Here’s the most common example of someone who has a normal BMI but is overfat: a very sedentary elderly person who looks slim, but has very little muscle. As the saying goes “use it or lose it” and they’ve lost it.

A clinician from Arizona has taken it upon himself to redefine the terminology associated with excess body fat. He claims that overfatness gets missed in too many people. The problem he sees is that people who could begin treatment with diet, exercise, and medication if necessary are being missed. He outlined his arguments in a paper published in January 2017 (1), but it was his paper published in July that lead to headlines (2).

He and his co-authors examined the BMIs of people in countries all over the world. Using prior studies that estimated the number of normal-weight people who are overfat, ranging from 9.7% to 20%, he then applied that to the normal-weight populations (as assessed by BMI) in the top 30 developed countries in the world. That’s how they derived the headlines of over 90% overfat—not just in the U.S. but also New Zealand, Iceland, and Greece as well. To be fair, this applied only to males. Don’t rest on your laurels, ladies. All the same countries were greater than 80% for females.

 

The Problems

There are three with his approach in my opinion. First, adding another definition to replace BMI doesn’t really help people or their physicians as he implies. Confirming a person with normal BMI is overfat would require a more advanced exam or assessment of body fat. I’m not sure that’s practical.

Second, I looked at his work from every direction and couldn’t get the numbers to work. If 70% of Americans are overweight or obese and you add 20% of the remaining 30%, it adds up to 76% not 90%. Even if the numbers worked, the statistic would apply to a physician’s total number of patients. There would be no way to identify who is overfat without additional testing.

Third, there’s another group that needs to be addressed, and that would be those who are overweight according to their BMI but are metabolically healthy. In fact, that’s a significant problem today. Even after losing over 30 pounds, my BMI is still in the overweight category. By every test of metabolic fitness—blood pressure, cholesterol, HbA1c, or insulin—I’m at no additional risk of heart disease, yet I’m still classified as “at risk” due to my BMI. I think that’s a greater issue and will be more so as healthcare gets debated. Is your BMI over 25? You’ll pay more, even if your test results are stellar.

 

The Bottom Line

I agree with the concept that the author put forth: there are people with normal BMIs that are overfat, and they’re at greater risk for CVD and metabolic diseases. But new definitions aren’t necessary. What is necessary is identifying who is at risk. That will only occur when doctor and patient meet face to face. When was your last doctor’s appointment?

What are you prepared to do today?

Dr. Chet

 

References:
1. Front. Public Health 4:279. doi: 10.3389/fpubh.2016.00279.
2. Front. Public Health 5:190. doi: 10.3389/fpubh.2017.00190.