Tag Archive for: BMI

Obesity: A Man-Made Disease

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In order to determine whether obesity is an untreatable disease without pharmaceuticals, I took a look at BMI data since 1960. In comparing the BMI of people in the lowest income brackets with the highest income from 1960 through 2024, the lowest income group is always about one BMI unit above the highest income group. The adjusted mean is roughly a BMI of 27 for the poor people versus 26 for the richest people. That continues until the mid-1980s. After that point, the mean BMI continues to rise for the next 40 years—a mirror image with the same one BMI-unit difference.

Mid-1980s

What happened in the mid 1980s that caused the surge in obesity? After checking various sources, there appear to be three factors, not ranked in any particular order.

  • The mid-1980s saw increases in two-income families. There are plenty of economic reasons for that, but the net effect was less time spent preparing food in the home and a reliance on convenience food purchases.
  • There was an increase in fast-food drive-thrus and take-out foods. Since COVID, there is more reliance on food delivery.
  • The mid-1980s saw an increase in ultra-processed foods. Using inexpensive ingredients, particularly carbohydrates and fats, and filled with flavor enhancers that accented the salty and umami, the amount of ultra-processed food has risen to over 50% of the typical American’s diet.

She was asked, “If people stop using GLP-1, will they gain back the weight?” She said yes because there’s no other way to maintain weight loss because of the fat setpoint. I just can’t accept that premise.

The Bottom Line

Overweight and obesity appear to be man-made diseases because of the environment we live in today with so much easily available food. However, I cannot accept that the fat setpoint is permanent. Yes, there are many factors in the brain, the pancreas, and the digestive system that control the feelings of hunger and the anticipation of food, but that doesn’t mean you really need nutrition. You and I just have to learn to ignore those signals that say, “what will my snack be?” when we’re still stuffed from dinner. We must take command. I’m not suggesting it will be easy, but it’s not impossible. In my mind, it’s a lot easier than taking a medication every day for the rest of my life.

What are you prepared to do today?

        Dr. Chet

References:
1. Int. J. Environ. Res. Public Health 2024, 21, 73.
2. Stat Pearls. 2025. Obesity and Type 2 Diabetes

Is Obesity a Disease?

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In a podcast about GLP-1 receptor agonists and several new medications that are under development, the expert was a researcher on the cutting edge of what these peptides can do for weight loss. A couple of things she said didn’t sit right.

One was that obesity is a disease of genetic tendencies to store fat more effectively and create a body-fat setpoint. The implication is that in a land of food abundance, specifically ultra-processed food, the setpoint could be raised but never lowered without medical intervention. The second was that these medications are the best solution for obesity, and thus people will have to take the medications for life or they’ll gain back weight.

According to the World Health Organization and just about every other medical society in the world, overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. But is it as simple as that? Based on a recent paper, the risk of getting type 2 diabetes is 7% to 12% in men and women at a BMI of 30; as BMI increases to over 40, the risk goes up to 74% for both men and women. It’s not an excuse to stay obese, but does it mean someone who is obese will get the diseases associated with obesity?  I have more questions, and I’ll cover them on Saturday.

Insider Conference Call is tomorrow night. The topics of the evening are reviewing the top five foods that prevent cancer as well as answering Insider questions. Interested? Become an Insider by 8 p.m. Wednesday and you can join in.

What are you prepared to do today?

        Dr. Chet

References:
1. Int. J. Environ. Res. Public Health 2024, 21, 73.
2. Stat Pearls. 2025. Obesity and Type 2 Diabetes

Again with the BMI?

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I got an email from a long-time reader about a recently published study comparing BMI calculated from height and weight with percent body fat calculated via Dual Energy X-Ray Absorptiometry commonly called DEXA. The objective of the study was to see if BMI was accurate in predicting the differences between underweight, normal weight, and several degrees of overweight and obesity with measure of body fatness.

Their subject pool was 1,351 Caucasian men and women 18–98 years old. This was a cross-sectional study (and more than likely a retrospective study) of patients in Italy who had their body fat assessed via DEXA between 2013 and 2024. While this paper contained hundreds of numbers, the essence of what they found was that for those with normal-weight BMI, body fatness was accurate, but for underweight and overweight and obese subjects, BMI under or overestimated their actual body fat; in the chart above, a red dot indicates someone whose BMI was misclassified. The authors felt that the World Health Organization should consider more research because the misclassification may impact diagnostic capability and thus lead to unnecessary treatment protocols.

Why BMI Should Still Be Used

I think the researchers are wrong in their conclusion for the following reasons:

  • While there were definite points where people were misclassified based on the graphic presentation of all data points, it was mostly on the margins. Is there a difference between a BMI of 24.5 versus 25.5? Is there a real difference in a person who has a BMI of 33.0 versus 36.0? Because of the way the data were analyzed by weight classification, the measure loses the nuance.
  • Regardless of the numbers, a physical examination by the healthcare professional should confirm whether a person is normal weight or overweight based on the fluffiness factor. People of the same height and weight may look muscular or like the doughboy of commercials.

The Bottom Line

The question of using BMI as a measure of body fatness in large groups will probably never be over. But when assessing large groups of people, it’s still the best measure for an overview of whether a population is underweight, normal weight, or overweight. If people really need to know more, they can always pay to have a DEXA scan done.

On a personal level, will it really give you any more information than when you stand naked in front of a mirror? When you know, you know. The important question is what are you going to do about it?

What are you prepared to do today?

        Dr. Chet

Reference: Nutrients. 2025. https://doi.org/10.3390/ nu17132162

Are We Done with BMI?

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Body mass index has been used for decades as a way to assess whether someone is at a healthy body weight for their height. For just about as long, it’s been under attack for the people who feel it was not representative of their body composition; high muscle mass and bigger bones were two of the complaints. I’m not going to disagree, within reason, but as a way of assessing a population in large studies, it can give us some indication of how body mass is related to health.

A recently published study has called into question the use of BMI as a predictor of mortality. Researchers used the data from the 1999–2000 National Health and Nutrition Examination Survey (NHANES) to compare BMI with a method of measuring body fat called bioelectrical impendence analysis (BIA). The subjects had all metrics measured when that wave began and were 20–49. Then they obtained death certificates for everyone in the study who died in the 25 years since.

The results presented in hazard ratios demonstrated that BIA and waist circumference were significantly related to all-cause and CVD mortality while BMI was not significantly related to either. In the discussion, the researchers suggested that BIA for determining body fat percent be used in clinical settings to assess patients at risk for increased risk of dying. Is that a good idea? Should we throw out BMI? I’ll let you know on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Ann Fam Med 2025;23:Online. https://doi.org/10.1370/afm.240330

“Watching” Your Diet and Workouts

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While the strategy for eating less I described on Tuesday used no type of tracking, this story is going to be the opposite. I ran into another person who has spent a couple of years focused on getting to a normal body weight. A couple of injuries playing sports set him back a little, but as we talked and I relayed the story from the day before, he said he was just the opposite: he tracks everything on his watch.

He records every meal—including the fast food breakfast sandwich he was eating; a client had brought it in and he felt he needed to explain his food choice to me. Remember, every food is acceptable as long as you track the frequency and amount. He continued that he tracks every workout—two days running, two days swimming, a spinning class, and he tries to run over the weekend. He can chart just about everything to monitor progress. He’s reached his weight-for-height goal and intends to keep up the lifestyle, because now, it’s his lifestyle.

Two different people, two different approaches—both worked. I’ll bet you have a story yourself. If not, you can write yours now, this year in 2025, so you can share it. It may inspire others. If you have one that’s worked for you, let me know how you did if you want me to share it with our group. Science takes you only so far; it’s how you make science work for you that’s important. Eat better. Eat less. Move more. And do it your way.

What are you prepared to do today?

        Dr. Chet

“I’ll Have What She’s Having”

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My philosophy of getting to a normal weight and staying there is to find out what works best for you by trial and error. When you find something that works, stick with it. This week, I’m going to relay the conversations I had with two people within 24 hours and how they approached weight reduction.

I recently saw a physician I hadn’t seen in three or four months, and I noticed he appeared to have lost some weight. I commented that he looked leaner than the last time I saw him. Many people ask how a person lost the weight, but I think that’s a personal thing; if someone wants to share it, great. Evidently he decided he’d share it.

He knew that he was way over his weight for height based on BMI; he also relayed the fact that he didn’t want to track his calories. What he decided to do was to eat the way his wife ate. She’s about 5’ 1” tall and weighs 110 pounds; she’s always maintained that weight with no effort. He decided to eat the food that she ate in the serving size that she ate. I’d never heard that from anyone before, and I thought it was brilliant. The result of following that pattern over a number of months was that he had lost 45 pounds and still had about 15 pounds to go to get to his normal weight for height.

When a couple do things together, it can make things so much easier, but it doesn’t have to be a couple. If you can observe people who appear to be lean and a normal body weight, just watch the amount of food they eat as well as the types of food they eat. It always comes down to eat less, eat better, move more. As I said when I started, we just have to figure out how to do that for ourselves to find out what works best. Next story on Saturday.

What are you prepared to do today?

        Dr. Chet

BRI: It Just Doesn’t Matter

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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

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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

Your BMI and Shrinkage

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I received several interesting questions regarding the loss of height and its impact on BMI: should you use your current height or your tallest height? I checked the research and found some interesting ideas, but there’s no direct answer.

While it may change slightly over time, your current height should be used to estimate BMI. You’re measuring shorter than you were when you were younger not because you’re stooping (or melting like the Wicked Witch of the West), but because the vertebrae lose bone mass and the disks between them lose fluid and get smaller. You’ve also probably lost muscle mass, but that can be regained; when bones and discs degrade, it’s not reversible as far as we know. That may mean that a person, including yours truly, has a lower target to get to normal weight for his current height.

A new theory of obesity on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: J Am Geriatr Soc. 2012. https://doi.org/10.1111/j.1532-5415.2011.03832.x

The Bottom Line on the Blue Zones

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The docuseries on Blue Zones demonstrated that it really isn’t complicated to live to 100: find a purpose, a reason to get up every morning, remain physically active, eat reasonably with a focus on plant-based sources for food, and develop a social group that can provide support through the various stages of life.

The docuseries ended with the writer working to create Blue Zones in different cities throughout the USA. That part is complicated because it involves community buy-in from government, health and healthcare officials, as well as professionals from nutrition, exercise, and community planning.

The Most Important Thing

After giving it a lot of thought, I’ve come to the conclusion that the most important thing that anyone can do to live well to 100 is this: get to a normal body weight and stay there. Not everyone who actually was 100 years and older was thin, but they had already made it to 100.

Getting to a normal weight reduces your risk of just about every degenerative disease and reduces the stress on your joints; Paula adds that it also greatly expands your clothing choices. You may never be able to do the splits like the man in the photo, but you’ll be able to do more than you do right now. Genetics is always there to blindside us, but even with that unknown, we can be in a better position by being a normal body weight and maintaining it.

The Blowback Was Instant

I spent last weekend with several thousand people, and I enjoyed every moment. I was asked many times what is the most important thing to be healthy, and my answer was always the same: find a healthier way to eat that you’re willing to stick to for the rest of your life, get to a normal weight, and stay there.

Some replied that “if I got to that weight, I’d look like a skeleton.” Then they would tell me what weight they think they can get to; I gave no quarter, no permission to say that’s good enough. How long that takes you to do could be one, three, maybe ten years. If you’re 43, that means you’ll be 53 and that’s just when everything begins to decline body-wise. You’ll be better able to handle it.

Here’s a simple way to start that you can begin this minute: cut out sugary and ultra-processed foods as much as you can. Then you can go on to find more vegetables you like, learn to cook with less fat, and so on, but you can say no to that donut or cookie right now.

What should you weigh? Here’s a link to the BMI chart at drchet.com. Note that there are guidelines to determine whether you’re big-boned or small-boned, and that affects your goal weight.

The Bottom Line

I would ask nothing of others that I wouldn’t do myself. Getting to a normal weight within a year is my goal; redistribution of that weight may take another couple of years. So what? I don’t know if I have the genes to live to 100, and I don’t know whether that’s my goal. I just want to be able to live like I want every day I’m alive.

No matter your age today, you can help yourself live well longer, and it starts by getting to that normal weight. I know you can do it.

What are you prepared to do today?

        Dr. Chet