A ‘Sweet Spot’ for Heart Health

As I understand it BMI was initially used during the Civil War. It’s not a good statistic but so easily calculated that it’s endured. Percent body fat and distribution of that fat are indicators of health problems. Yet I’ve never (I’m 66 diabetic, heart arrhythmia walk 5 mi a day, great VO2 max) had a Doctor calculate it. So I must assume t it’s not really that important. ?

Fun but pointless information in this article. Lose excess weight, eat right, exercise and you will feel better for more years before you die. But please note, you will die either way; and the real choice is how long and how badly you want to be disabled and diseased before you go. The real objective is about extending youthful strength for as long as you can.

“If you’re healthy, you can lower your risk of cardiovascular disease by being as slim as possible within the normal range of B.M.I.” There is no evidence whatever in the study for this conclusion. Correlation is not causation. The literature is full of observed relationships that do not hold up when interventions are done.

"Sweet Spot" is the name of cook book by my friend Bill Yosses, former pastry chef at the White House, where he uses less sugar in everything. I use less sugar all the time in pastries in my cooking classes in Dijon, France. www.i-food-france.com Bill is up for The James Beard Award!

If you spend time reviewing the data and looking over the "study" (free link in article) you quickly see this to be just another attempt to publish by making claims that are absurd. Yes, there is "statistical significance" reported, but the degree of change if you look at the HRs in not relevant and the statements of percentage increases in risk are more speculative than significant.

BMI is _not_ a measure of adiposity, except at the extremes. When they looked at actual measures of adiposity, they found much better correlations with heart disease risk. In other words, the so-called "obesity paradox" disappears when we account for fat mass vs. muscle mass.

Looking at Figure 1 in the study, which is free in this case and can be seen by clicking on the link in the article, shows the association of CVD risk with various measures of obesity. It's clear that only the BMI chart shows the so-called obesity paradox. There's no hint whatsoever of the paradox in all of the other measures including waist circumference, waist-to-hip ratio, waist-to-height ratio and percent body fat as determined using bioimpedance measurements. In each of these other associations the risk is log-linear all the way down to the lowest measures of obesity and in both men and women. The risk not only does not rise below some threshold, as it does for BMI but shows no signs of diminishing returns. In other words, there's no point at which the curves flatten out; they keep going down with lower measures of obesity, It's also worth noting that the percent body fat for men is not all that strongly associated with CVD risk but the waist-to-height ratio is strongly associated. That confirms that it's abdominal fat that's the main cause of increased CVD risk at least in men. That result may not hold for women or for cancer risk or total mortality but this study is focused only on CVD. The fact that the obesity paradox only shows up when using BMI as a measure of obesity pretty much discredits all studies showing an obesity paradox that depend solely on BMI as a measure of obesity, whether looking at CVD, cancer, diabetes or all-cause mortality.

How in this study or any study account for the muscle content of the subjects. I have a BMI of 25 but body fat of less than 10%. I am a competative rower and train 9 hours a week. There are many people that have plenty of fat and low muscle that have a lower BMI than I do. BMI is out of date and needs to be replaced. While I am at it the max heart rate of 220 minus your age is bougus as well. At 65 my training heart rate is 155 and I hit 195 during a race.

BMI is well known to be flawed. Research on the negative health effects of being overweight show it's primarily abdominal visceral fat deposits that are the problem. That's why waist circumference, waist-to-height ratio and and waist-to-hip ratio are much more informative than BMI. Why the media continues to focus on BMI is a mystery considering these alternative measures of obesity are simple to perform without special equipment. The only better measures of visceral fat deposits require expensive technology including CAT scans, MRI and DEXA scans all of which can accurately measure exactly where visceral body fat deposits are located and exactly the amounts involved. Non-alcoholic fatty liver disease as well as pancreatic fat are well known examples of visceral fat that can be seen with these scans. Studies show, for example, that losing pancreatic fat can reverse type two diabetes. There's also the issue of ectopic fat deposits in muscle which may be more problematic than subcutaneous fat which is likely does not contribute to increased health risks. BMI not only lumps these kinds of fat deposits together but also includes lean muscle mass. There is therefore no such thing a BMI sweet spot. And we also know that people who practice calorie restriction have very low body fat, much lower than levels considered normal or healthy. And endurance athletes also have on average very low body fat percentages, which may account for much of the health benefits of exercise.

Once again the uselessness of BMI is demonstrated. First study NYT has reported wherein other, more meaningful measures of fatness are mentioned. They seem to fit the data better. Duh?

If you go the the study link, the data really show something different then there being a sweetspot. The data show that, with the exception of some people with very low BMIs, that the fatter you are and the more fat you carry on your waist, the more likely you are to suffer an adverse heart event. It's a linear relationship. The skinniest people suffered the fewest heart events. The low BMI numbers are suspect, partly because data points are fewer and more divergent in that cohort and the data really don't show that much. One man in 17 of those with a BMI of less than 22 suffered a heart event. One man in 17.6 of those with a BMI equal to or greater than 22 suffered a heart event. Not much added risk. And for women, the risk was reversed. One woman in 42.2 with a BMI of less than 22 suffered a heart event. One woman in 29.4 with a BMI equal to or greater than 22 suffered a heart event. The people in this study also drink a lot compared to the average American. Only 4.4 percent of the women and 7 percent of the men drank less than a drink per week. In America, 60 percent drink less than a drink per week. And we know that alcohol has confounding effects on heart disease.

The BMI of study participants was measured in the latter third or quarter of their lives. In almost everyone, weight consistently rises throughout the first 50-60 years of life. If this data is to be taken at face value (cause and effect of BMI not reversed, for example), then it suggests a longevity advantage for those who are slender for the first several decades of life.

This was obvious all along. The conclusion of the study is: Sick people with low BMI are either deathly ill or remarkably healthy.

This is deception by setting up a “straw man.” First, the “obesity paradox” —that somewhat overweight people end up living longer than lighter and “normal-weight people—is not about cardiovascular (CVD) events like just heart attacks and strokes. It is about All-Cause Mortality. Yes, some data indicate that the CVD subset may not show the paradox effect, but it is all-cause mortality that really counts. You have twice the chance of dying from non-CVD morbidity than a CVD one and it is non-CVD mortality that higher BMIs are most protective of. See, e.g., PMID 22450395. Note that the authors could have very easily analyzed and reported all-cause mortality here—but they didn’t. Why not? What are they trying to hide? They have the data. Second, the average age here was only 55 and they were followed for only 5 years. The “obesity paradox” covers people older than 65, not young people. See the results from a 2013 systematic review and meta-analysis of 97 separate studies on the association of all-cause mortality and BMI, with a combined 2.88 million people and more than 270,000 deaths, from the Journal of the American Medical Association, “Association of All-Cause Mortality with Overweight and Obesity Using Standard Body Mass Index Categories: A Systematic Review and Meta-Analysis,” JAMA. 2013;309(1):71-82, Flegal et al., PMID 23280227. See, e.g. Table 2. The obesity paradox grates the established medical profession. Thus we get straw men and sleight-of-hand, as here.

The more important outcome is total mortality. What was the relationship to BMI?

Just so everyone knows, sugar and carbs cause heart disease, not fats or not good fats, this is something that has not been out there so you all know this. My doctor told me and I kinda did not believe but had to change my diet for other reasons. I eat a low carb diet and to not get to thin I added olive oil, coconut oil, good cheeses etc.....stopped all sugar. My last blood test came back amazingly excellant Good was perfect and LDL was low, first time for me that LDL was low.

According to researchers, there are 5 ways to measure obesity, this article begins. Then the article went on to describe only one, BMI. Why not the other 4?

Once again we are treated to a correlations=causation conclusion that is not actually made by the study. It may be that meeting a target BMI will reduce your chances of having cardiovascular disease or it may be an irrelevant marker of the real causes.