TCS Daily

Junk Science Is Contagious

By Jonathan Robison, PhD, MS - September 6, 2007 12:00 AM

After decades of research and a plethora of seemingly infinite numbers of dead-end leads, scientists have finally discovered the cause of the biggest Public Health scourge of our time - Obesity. And what is that cause? Well, it is not lack of exercise, it is not what we are eating, and it is certainly not what is passed on through our genes. No, according to research recently published in the prestigious New England Journal of Medicine, the cause of obesity is...fat people. You heard me correctly. The obesity epidemic is caused by - just what you might expect - fat people passing on their fatness to other people and making them fat.

In an amazing stretch of what can possibly be considered serious research, scientists from Harvard Medical School and the University of California dredged up and performed high-tech magic on some almost 40 year old data from the Framingham Heart Study. Their amazing explanation of what their plans were and what they believe they found is best expressed in the words of the lead author of the study Nicholas A Christakis of Harvard University:

"It's almost a cliché to speak of the obesity epidemic as being an epidemic. But we wanted to see if it really did spread from person to person like a fashion or a germ. And the answer is, Yes it does."

On what firm foundation of scientific evidence are they basing this almost comical, yet somehow still unnerving claim? In fact, it is based on an observational study of some 2300 people from the "offspring cohort" (siblings) of the original Framingham Study. The researchers looked at the body mass indices of individuals that these cohort offspring indicated on their original administrative tracking sheets for the Framingham study as people they would recommend to contact (otherwise known as friends and families) to help facilitate follow up of the study. They then compared BMI changes measured in these individuals during numerous three year periods between 1971 and 2003 with BMI changes of the people in the cohort. What were the startling findings? An individual's chances of becoming obese were 57% greater if they had a friend who became obese over a certain period of time. And what was the authors' conclusion?

"It's not that obese or non-obese people simply find other similar people to hang out with, rather, there is a direct causal relationship".

How does one conclude a direct causal relationship from an observational study? Bald men are more likely than men with a full head of hair to have a heart attack. Can we conclude from this that they should buy a toupee or begin using Rogaine lotion to lower their risk? And what about that little nasty episode with hormone replacement therapy just a few years ago? Remember when women were told that since there was much more heart disease observed after menopause the reason must be the loss of hormones - and that therefore hormone replacement therapy must be the answer? Oops, wrong again. The bottom line is that what you get from observational studies like this one are hypotheses which then must be validated by research that actually implements experimental interventions to prove or disprove them.

So, what some would consider fairly outrageous claims by the authors like "once one person becomes obese for whatever reason, it may make it more socially acceptable for people close to him or her to gain weight," and "what spreads is an people around you gain weight, your attitudes about what constitutes an acceptable body size change, and you follow suit and emulate the body size," may be interesting hypotheses, but until they are tested experimentally, they remain that -- just interesting hypotheses.

The same is true for the following statement, made by the lead researcher, summing up the growth of the obesity epidemic, saying that this social emulation of other people's increased body sizes "may cross some kind of threshold, and you can see an epidemic take off. Once it starts, it's hard to stop it. It can spread like wildfire." The jump from association to cause may be most evident in the conclusion drawn by the researchers with regard to the association of weight gain in friends living far from each other. "We were stunned to find that people who were hundreds of miles away had just as much impact on a person's weight status as friends who are next door." Send for the toupees and the Rogaine!

In order to soften the blow of these inappropriate and unscientific jumps from association to cause, the authors invoke the use of the engaging term "social contagion" to describe what is happening. Contagion comes from the latin contagio meaning to touch and is defined in the American Heritage Dictionary as "disease transmission by direct or indirect contact" and "the direct cause such as a bacterium or virus, of a communicable disease...a harmful corrupting influence." Clearly fat people are the "harmful" and "corrupting" cause of obesity.

If these seasoned scientific researchers don't know (or choose to ignore) the difference between cause and correlation, we certainly can't expect the media to do any better. Clearly this is the case, as the following headlines signaling the release of the story certainly verify.

New York Times -- Obesity is Contagious, Study Finds.

NPR Morning Edition -- Are Your Friends Making You Fat? -- Your best friend could be making you fat

Though this confusion between cause and correlation is enough to invalidate any of the conclusions drawn from this study, it is certainly not the only problem. The study group includes only 45% of the original nonrandom cohort of 5124. The study group consists of all white, mostly well-to do individuals - certainly not representative of the United States population as a whole.

Perhaps most disturbing is that, in spite of the fact that the vast majority of media images relating to the article were pictures of women, it turns out that the supposed impact of a friend's obesity on a friend's obesity (the strongest association of the BMI's of all those observed) was only significant when both friends were male.

Have the researchers not heard that, aside from not being a good predictor or mortality or morbidity in males or females, use of the BMI is particularly problematic with males because it does not distinguish between muscle and fat and thus mislabels significant numbers of men as being overweight and obese when they are not? (see table below)


George W. Bush 26.3 Overweight

Will Smith 27 Overweight

Yao Ming 27.7 Overweight

George Clooney 29 Overweight

Johnny Depp 29.8 Overweight

Matt LeBlanc 30 Obese

Tom Cruise 31 Obese

Shaquille O'Neil 31.6 Obese

Arnold Schwarzenegger 33 Obese

As absurd as the conclusions and proposed explanations for the findings of this research are, the lack of connection to reality of the proposed implications for public health certainly take the cake. After claiming "social contagion" to be an important factor in the obesity epidemic, the authors go on to say that "it may be possible to harness the same process to slow the spread of obesity." The suggestions that follow can only be described kindly as out of touch with reality, not to mention a bit frightening - less kindly as science in "la-la land." The authors suggest that we should try "treating people in groups," because people who are close to someone who loses weight are "more likely to get thinner." Seems to me there have of research, perhaps thousands of articles on this subject all coming to the same conclusion - it doesn't work that way. Then the authors hypothesize that, all of this research (much of it including actual interventions and experimental data) may be wrong. "Medical and public health interventions might be more cost-effective than initially supposed, since health improvements in one person might spread to another." Again, given the complete lack of support for this conclusion in untold studies over the last 40 or so years, one has to wonder upon what planet these researchers are looking down from their ivory towers.



Shut up and listen to the "scientists"!
Although it is the fault of the media for sensationalizing and misrepresenting science it is also the fault of the scientists for not countering such stupidity.

It would also help if people had more insight as to how science works and the nature of the such studies. Such ignorance is on constant display in the AGW arguments on this forum as a great many believe that consensus, even if none exists, or the MSM's version of it equals scientific validity.

Junkscience is a quite the rage and it would be great if the scientific community would worry less about grants, fame, and media hype and begin to combat it.

exactly right
It saddened me to today read that G.W. Bush has been drawn fully into the AGW policy crowd. Sad really, especially when the state of the science is no where near exacting on Global Warming, the cause of Global Warming or the effect and duration of warming effect.

The same is true here. Three things have been documented to cause obesity; genetics, lack of exercise and diet. The media's desire to pick up every strange study and report it as fact is just making an already bad situation worse.

Is science ever going to get back the the job of finding the facts and improving the knowledge base of mankind?? Probably not. Money is so much easier to get when your claims are outrageous!

Heres's some "science" for ya

'These stories do nothing to promote science. They sell products and pay money, misrepresent the notion of doing research, and sell the idea that scientists are irrelevant boffins.'

BMI and body fat percentage
This is a good illustration of why the BMI is bogus. People who are lean and muscular have a high BMI even thought they are fat. A much more useful indicator is body fat percentage, which you can easily have measured at any gym in the U.S.

I would like to see the statistics for obesity based on body fat percentage measurement.

I love that term "boffin".

It makes sense
It makes sense that people who hang out with fat people are less likely to think it bad to be fat and therefore more likely to not fight gaining weight themselves.

Just like stupid people are more likely to hang out with stupid people. By the way, who funded this study?

Survival of the fattest?

Myth of social contagion
The myth of fatness spreading by "social contagion" is as much junk science as is the myth that cannabis is a "gateway" drug. Same junk science. Different political reactions. Go figure.

fat police
It seems like liberals are just plain offended by seeing fat people, because it's not considered trendy right now, whereas Rubens would probably approve, as well as many other cultures like the Samoans, etc. But as usual, liberals are busy-bodies with heavy fascisst tendencies; they always want to force other people to do what they want.

BMI rates medium sized people as overweight or obese
George Bush doesn't look overweight to me, nor do any of the others mentioned! Do people need to be built like a beanpole to satisfy these people? Just WHAT do these nutts consider 'normal' weighted people? How anorexic would you have to get before they'd consider you underweight? Ban all this excessive concern over what somebody else weighs! Maybe we could redirect some of that 'concern' towards something that would actually do people some good instead of implying muscular built people have a weight problem. When I was growing up, one man built like Swartzenegger was worth more than ten who would rate 'ideal weight' on that stupid BMI index.

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