In a current New York Times opinion column, dietitian Christy Harrison, an “intuitive eating coach” and creator, responded to a fellow clinician who had questioned a few of her ideas on the hyperlink between being obese and growing different medical circumstances.
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In a current New York Times opinion column, dietitian Christy Harrison, an “intuitive eating coach” and creator, responded to a fellow clinician who had questioned a few of her ideas on the hyperlink between being obese and growing different medical circumstances.
[partner-box]Harrison famous that though most well being professionals have been taught that greater physique mass index (BMI) causes poor well being outcomes, she wrote, “unfortunately, that just isn’t true.”
She added: “We have a host of issues associated with high B.M.I.s. But correlation doesn’t prove causation, and there’s a significant body of research showing that weight stigma and weight cycling can explain most if not all of the associations we see between higher weights and poor health outcomes.”
We determined to research the purpose she was making, which is on the middle of a bigger, often-heated debate about whether or not it’s doable to be obese and wholesome on the identical time — a perspective advocated by the “Health at Every Size” motion, of which Harrison is part. With almost 72% of U.S. adults considered obese or overweight, it is a urgent concern.
When we reached out to Harrison to search out out the idea of her assertion, she responded rapidly, citing two papers as her major sources.
The first, a 2011 piece revealed within the Nutrition Journal, argues it is perhaps higher to shift away from weight-loss efforts to bettering well being in different methods which can be weight-neutral.
Its lead creator, Linda Bacon, a professor on the University of California-Davis, wrote “Health at Every Size: The Surprising Truth About Your Weight,” a 2010 guide embraced by “fat acceptance” advocates.
It addresses Harrison’s first level with this: “While it is well established that obesity is associated with increased risk for many diseases, causation is less well-established.”
The different paper, a 2014 piece within the Journal of Obesity, makes related arguments.
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Causation, Correlation, Association: Let’s Unpack That
There is an previous noticed utilized by most statisticians: Correlation doesn’t equal causation.
But what does that imply? Let’s use a faux instance: Some folks have bother seeing at evening. Turns out all these folks ate carrots. Ergo, there might be a correlation between consuming carrots and evening imaginative and prescient issues.
That doesn’t show anything, although, equivalent to causation. Correlation is critical when attempting to find out causation, however doesn’t show it.
“Epidemiological studies never show causation, only association,” stated Dr. Samuel Klein, director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis.
To set up trigger, epidemiologists want extra proof.
The greatest approach, thought of the “gold standard,” is to randomly assign folks to 1 group or one other ― feeding one group carrots and withholding carrots from the opposite. Researchers would then monitor any distinction in how many individuals develop evening imaginative and prescient issues.
That’s nifty, however not all the time doable or moral. One couldn’t, for instance, randomly assign some folks to a bunch after which trigger them to turn into obese.
Instead, researchers use totally different types of studies, equivalent to those who evaluate teams of people that have already got the attribute — say, carrot consuming or being obese — with those that don’t to see if patterns emerge.
They use strategies to manage for issues which may have an effect on the outcomes, equivalent to age, gender, revenue stage, whether or not an individual smokes and different elements. Then they’ll estimate how robust of an affiliation or correlation they see.
With smoking and lung most cancers, very robust associations have been seen, resulting in the conclusion that, sure, smoking causes lung most cancers. But does extra weight trigger different well being circumstances, equivalent to diabetes, coronary heart illness, most cancers, sleep apnea or joint issues?
“With the case of weight, the associations are much weaker,” stated Kendrin Sonneville, assistant professor of dietary sciences on the University of Michigan School of Public Health.
So on this level, Henderson’s assertion holds up. Current scientific analysis helps a correlation between being obese and struggling poor well being outcomes, however it doesn’t definitively set up causation.
But others, particularly clinicians, say there may be little doubt that being obese strongly raises the danger of growing such well being issues.
“This isn’t up for debate,” stated Dr. Harold Bays, chief science officer for the Obesity Medicine Association, which represents practitioners who deal with obese sufferers.
“The overwhelming amount of clinical and scientific data supports obesity as a disease, both as a direct and indirect contributor to a large number of adverse metabolic and other health consequences,” he stated.
A 2018 Endocrine Society scientific statement, for instance, seemed throughout many research of obese and weight problems, concluding that the 2 contribute to “type 2 diabetes mellitus, cardiovascular disease, some cancers, kidney disease, obstructive sleep apnea, gout, osteoarthritis, and hepatobiliary disease, among others.”
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Then issues get murky.
Bays and the opposite specialists agreed that some people who find themselves obese may not develop different circumstances.
“It is absolutely true that not all cases of diabetes, hypertension, cancer and fatty liver are due to obesity,” stated Bays.
They acknowledged that individuals who fall into the class of being overweight or obese could even seem wholesome metabolically — at the least for some time.
But there’s additionally a warning.
“If you say, ‘Wait a minute, is their blood sugar where we want it … aren’t their triglycerides a little high and what about their blood pressure?’ And that’s not even to mention pain to the joints or sleep apnea,” Bays stated. “When you drill down, very few people would truly meet the criteria of being metabolically healthy but obese, and if you follow them for five or 10 years, now the majority are going to have something.”
What About The Stigma?
There’s been much less analysis round Harrison’s second level: that almost all, if not all, of the ailments related to being overweight or obese are brought on as a substitute by the stigma heavy folks face, or the yo-yo impact of weight-reduction plan, losing a few pounds after which gaining it again once more, in common cycles.
She pointed to analysis included within the paper by Bacon reporting that weight biking might result in hypertension, or hypertension. The analysis, nonetheless, discovered associations although not particular causation.
Similarly, in one other study Harrison offered, individuals who reported weight discrimination ― 6% of the pattern studied — had twice the danger of physiological stress over almost 10 years. Such stress might be related to Type 2 diabetes, hypertension and heart problems, the examine stated.
But most of these we spoke with strongly disputed the sweeping assertion that so many continual circumstances might be brought on by stigma and weight biking.
While these two issues can issue into well being issues, they aren’t accountable for a lot of the well being outcomes seen by her sufferers, stated Dr. Fatima Cody Stanford, an weight problems drugs doctor and an assistant professor of drugs and pediatrics at Harvard Medical School.
Stanford additionally takes concern with advocates who promote the concept being obese isn’t an enormous well being danger issue.
“The Health at Every Size movement goes against what we know about obesity as a disease,” Stanford stated. “Their aim in that movement is to not learn the science.”
Our Ruling
Harrison stated the notion greater BMI causes poor well being outcomes “just isn’t true” ― including that “we have a host of issues associated with high BMIs. But correlation doesn’t prove causation, and there’s a significant body of research showing that weight stigma and weight cycling can explain most if not all of the associations we see between higher weights and poor health outcomes.”
On a strict studying of the science, she has a degree. It could be very troublesome to show definitively what causes illness, and exhibiting “correlation” is a distinct discovering than causation. However, she seems to use this normal selectively, utilizing it each to undermine the connection between excessive BMI and poor well being outcomes, and as proof of how weight biking and stigma are linked to sure continual well being circumstances.
But within the case of weight problems, researchers in a number of research nationally and worldwide have proven particular hyperlinks between being obese and growing ailments, equivalent to diabetes, and circumstances, equivalent to painful joints. There is much much less proof for the function that weight stigma and yo-yo weight-reduction plan has within the improvement of these medical issues, though the specialists urge persevering with analysis into these questions.
We price Harrison’s assertion as Mostly False.
This story might be republished without cost (details). Harrison famous that though most well being professionals have been taught that greater physique mass index (BMI) causes poor well being outcomes, she wrote, “unfortunately, that just isn’t true.”
She added: “We have a host of issues associated with high B.M.I.s. But correlation doesn’t prove causation, and there’s a significant body of research showing that weight stigma and weight cycling can explain most if not all of the associations we see between higher weights and poor health outcomes.”
We determined to research the purpose she was making, which is on the middle of a bigger, often-heated debate about whether or not it’s doable to be obese and wholesome on the identical time — a perspective advocated by the “Health at Every Size” motion, of which Harrison is part. With almost 72% of U.S. adults considered obese or overweight, it is a urgent concern.
When we reached out to Harrison to search out out the idea of her assertion, she responded rapidly, citing two papers as her major sources.
The first, a 2011 piece revealed within the Nutrition Journal, argues it is perhaps higher to shift away from weight-loss efforts to bettering well being in different methods which can be weight-neutral.
Its lead creator, Linda Bacon, a professor on the University of California-Davis, wrote “Health at Every Size: The Surprising Truth About Your Weight,” a 2010 guide embraced by “fat acceptance” advocates.
It addresses Harrison’s first level with this: “While it is well established that obesity is associated with increased risk for many diseases, causation is less well-established.”
The different paper, a 2014 piece within the Journal of Obesity, makes related arguments.
Causation, Correlation, Association: Let’s Unpack That
There is an previous noticed utilized by most statisticians: Correlation doesn’t equal causation.
But what does that imply? Let’s use a faux instance: Some folks have bother seeing at evening. Turns out all these folks ate carrots. Ergo, there might be a correlation between consuming carrots and evening imaginative and prescient issues.
That doesn’t show anything, although, equivalent to causation. Correlation is critical when attempting to find out causation, however doesn’t show it.
“Epidemiological studies never show causation, only association,” stated Dr. Samuel Klein, director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis.
To set up trigger, epidemiologists want extra proof.
The greatest approach, thought of the “gold standard,” is to randomly assign folks to 1 group or one other ― feeding one group carrots and withholding carrots from the opposite. Researchers would then monitor any distinction in how many individuals develop evening imaginative and prescient issues.
That’s nifty, however not all the time doable or moral. One couldn’t, for instance, randomly assign some folks to a bunch after which trigger them to turn into obese.
Instead, researchers use totally different types of studies, equivalent to those who evaluate teams of people that have already got the attribute — say, carrot consuming or being obese — with those that don’t to see if patterns emerge.
They use strategies to manage for issues which may have an effect on the outcomes, equivalent to age, gender, revenue stage, whether or not an individual smokes and different elements. Then they’ll estimate how robust of an affiliation or correlation they see.
With smoking and lung most cancers, very robust associations have been seen, resulting in the conclusion that, sure, smoking causes lung most cancers. But does extra weight trigger different well being circumstances, equivalent to diabetes, coronary heart illness, most cancers, sleep apnea or joint issues?
“With the case of weight, the associations are much weaker,” stated Kendrin Sonneville, assistant professor of dietary sciences on the University of Michigan School of Public Health.
So on this level, Henderson’s assertion holds up. Current scientific analysis helps a correlation between being obese and struggling poor well being outcomes, however it doesn’t definitively set up causation.
But others, particularly clinicians, say there may be little doubt that being obese strongly raises the danger of growing such well being issues.
“This isn’t up for debate,” stated Dr. Harold Bays, chief science officer for the Obesity Medicine Association, which represents practitioners who deal with obese sufferers.
“The overwhelming amount of clinical and scientific data supports obesity as a disease, both as a direct and indirect contributor to a large number of adverse metabolic and other health consequences,” he stated.
A 2018 Endocrine Society scientific statement, for instance, seemed throughout many research of obese and weight problems, concluding that the 2 contribute to “type 2 diabetes mellitus, cardiovascular disease, some cancers, kidney disease, obstructive sleep apnea, gout, osteoarthritis, and hepatobiliary disease, among others.”
Then issues get murky.
Bays and the opposite specialists agreed that some people who find themselves obese may not develop different circumstances.
“It is absolutely true that not all cases of diabetes, hypertension, cancer and fatty liver are due to obesity,” stated Bays.
They acknowledged that individuals who fall into the class of being overweight or obese could even seem wholesome metabolically — at the least for some time.
But there’s additionally a warning.
“If you say, ‘Wait a minute, is their blood sugar where we want it … aren’t their triglycerides a little high and what about their blood pressure?’ And that’s not even to mention pain to the joints or sleep apnea,” Bays stated. “When you drill down, very few people would truly meet the criteria of being metabolically healthy but obese, and if you follow them for five or 10 years, now the majority are going to have something.”
What About The Stigma?
There’s been much less analysis round Harrison’s second level: that almost all, if not all, of the ailments related to being overweight or obese are brought on as a substitute by the stigma heavy folks face, or the yo-yo impact of weight-reduction plan, losing a few pounds after which gaining it again once more, in common cycles.
She pointed to analysis included within the paper by Bacon reporting that weight biking might result in hypertension, or hypertension. The analysis, nonetheless, discovered associations although not particular causation.
Similarly, in one other study Harrison offered, individuals who reported weight discrimination ― 6% of the pattern studied — had twice the danger of physiological stress over almost 10 years. Such stress might be related to Type 2 diabetes, hypertension and heart problems, the examine stated.
But most of these we spoke with strongly disputed the sweeping assertion that so many continual circumstances might be brought on by stigma and weight biking.
While these two issues can issue into well being issues, they aren’t accountable for a lot of the well being outcomes seen by her sufferers, stated Dr. Fatima Cody Stanford, an weight problems drugs doctor and an assistant professor of drugs and pediatrics at Harvard Medical School.
Stanford additionally takes concern with advocates who promote the concept being obese isn’t an enormous well being danger issue.
“The Health at Every Size movement goes against what we know about obesity as a disease,” Stanford stated. “Their aim in that movement is to not learn the science.”
Our Ruling
Harrison stated the notion greater BMI causes poor well being outcomes “just isn’t true” ― including that “we have a host of issues associated with high BMIs. But correlation doesn’t prove causation, and there’s a significant body of research showing that weight stigma and weight cycling can explain most if not all of the associations we see between higher weights and poor health outcomes.”
On a strict studying of the science, she has a degree. It could be very troublesome to show definitively what causes illness, and exhibiting “correlation” is a distinct discovering than causation. However, she seems to use this normal selectively, utilizing it each to undermine the connection between excessive BMI and poor well being outcomes, and as proof of how weight biking and stigma are linked to sure continual well being circumstances.
But within the case of weight problems, researchers in a number of research nationally and worldwide have proven particular hyperlinks between being obese and growing ailments, equivalent to diabetes, and circumstances, equivalent to painful joints. There is much much less proof for the function that weight stigma and yo-yo weight-reduction plan has within the improvement of these medical issues, though the specialists urge persevering with analysis into these questions.
We price Harrison’s assertion as Mostly False.
