On Obesity, What the Researchers Didn't Find

By Sandy Szwarc

Several studies citing correlations between bad foods or sedentary habits and rising rates of obesity and type 2 diabetes have filled the news lately. The studies seem, at first glance, to confirm what "everyone knows" about why people are fat -- they eat too much "bad" food and exercise too little -- and what to do about it. But correlations can't hold water to sound clinical evidence.

While it's in our best interests to look past correlations for sounder studies and weigh them in light of the entire body of evidence, such studies aren't always easy to find. Like all food and health news, we typically only hear one side. And we almost never hear about the studies that disprove something or find something didn't work or isn't a health concern -- especially if they go against a popular belief.

However, studies disproving a concept are especially important and during the scientific process, ideas that have been disproven are thrown out and scientists move on to find the real explanations. But a classic earmark of pseudoscience ("false" science) is failing to abandon ideas and doggedly continuing to claim something is true or works regardless of overwhelming evidence to the contrary.

GUTS and DONALD

On the subject of the evils of sodas and snack foods, for example, here are a few new studies that barely made the news recently. Their negative findings were notably different from the popular axioms and yet they concur with a sizable body of such evidence.

Two different analyses from the Growing Up Today Study (GUTS), based at Brigham and Women's Hospital and Harvard Medical School in Boston, were released last month. GUTS is a databank of questionnaires about diet, lifestyle habits and health that were gathered from more than 16,000 children, 9 to 14 years of age. Their mothers are from the Nurses Health Study, the huge database of questionnaires gathered since 1976 from over 120,000 nurses. The study has the limitations inherent in population studies, but what makes these two studies from GUTS significant is that the researchers couldn't even find a connection between soda or snack (ice cream, candy, chips, sweet baked goods, etc.) consumption and weight among these kids after 3 years. In other words, fat children weren't eating more sweets than thin children.

What the GUTS research, led by Allison Field, did find, however, was that regardless of their overweight status, children who dieted gained significantly more weight compared to children who never dieted. This confirms another study these same researchers released last October which found the BMIs of girls who were frequent dieters versus those who never or rarely dieted were nearly 4 entire BMI points higher. This was after they accounted for all the other factors that could have explained the differences, including physical activity, television watching, etc. The researchers concluded their data suggest that dieting is not only ineffective but in the long-run may actually promote weight gain. And, indeed, clinical studies have confirmed just that.

Perhaps the most significant study to come out this month was the one that got the very least media attention. The results of the DONALD Study (Dortmund Nutritional Anthropometric Longitudinally Designed Study) were released from the Research Institute of Child Nutrition, Dortmund, Germany. This was a small cohort study on 228 nondieting children. The researchers themselves actually weighed the individual children and recorded their diets (the foods, amounts and eating occasions) at least ten times a year and followed them thusly for 17 years. They found that no identifiable dietary patterns during childhood or adolescence could explain their BMIs. While there were great differences in the children's diets, these differences were not related to their weights.

The GUTS and DONALD studies join a profusion of other studies, both clinical and epidemiological, over the past fifty years demonstrating that fat children and adults as a population normally eat exactly the same as thin people. And regardless of their diets, children will still naturally grow up to be a wide range of heights and body weights. "Multiple researchers, using a variety of methodologies, have failed to find any meaningful or replicable differences in the caloric intake or eating patterns of the obese compared to the non-obese to explain obesity," concluded David Garner, Ph.D. and Susan Wooley, Ph.D., for example, in their review of some 500 studies on weight in Clinical Psychology Review.

How Can This Be?

How can this be reconciled with the laws of thermodynamics? The findings seem at odds with what conventional wisdom might suggest to us about eating and weight gain.

One of the country's foremost obesity researchers, Jeffrey M. Friedman, M.D., head of the Laboratory of Molecular Genetics at Rockefeller University explains that the commonly-held simplistic belief that obesity is just a matter of eating too much and/or not exercising enough is "at odds with substantial scientific evidence illuminating a precise and powerful biologic system." According to his research and that of numerous others, obesity is the result of differences in biology and metabolism, not behavior, diet or the environment. Through their own volition, people can control their weight long-term to a very small degree. Even voluntary physical exercise has minimal effect, according to Friedman and Glenn Gaesser, PhD., exercise physiologist and obesity researcher at the University of Virginia. So, while better access to foods can account for some of the increases seen in the average height and weight of all people in developed countries -- 7 to 10 pounds in the U.S. since 1980s -- it's genetics and not the environment that accounts for the largest proportion of the differences in size among people, Friedman explains.

"The propensity to obesity is, to a significant extent, genetically determined," he says. Someone genetically predisposed to obesity "will become obese independent of their caloric intake" even when it's restricted to that of thin counterparts. "The heritability of obesity is equivalent to that of height and greater than that of almost every other condition that has been studied," Friedman states.

Negative studies disproving things "everybody knows" are important for leading us to sounder answers. The strongest research will never find proof of something that doesn't exist. Only pseudoscience can ever do that.


http://www.techcentralstation.com/100704F.html

From the linked article by the author, under the heading "Loopy Links" (how appropriate)

"Popkin could have mined that databank and pulled out anything...and has. For example, in a previous study he found grains, legumes and low-fat milk intake up among adults since 1965, along with significant decreases in calories and percentages of dietary fat. Yet he didn't tie these overall "healthful" eating trends to rising rates of obesity or type 2 diabetes. Why, that wouldn't have made sense."

Gee, if its not calories, and its not dietary fat ... can anyone here think of what IT might be ???

Cheers,


Malcolm

My perceptions are these:

The author is correct in that there are genetic ramifications, but the conclusion seems to be that weight gain is a lost cause, no one can do anything about it, you've inherited it and it's your fate in life. If you restrict calories you're no less likely to lose weight. Of course, there's no discussion as to whether all these kids were eating appropriate food for human consumption. The fact that some kids didn't gain weight was enough for these people to conclude that the food consumed was not to blame.

Since the turn of the last century the population has consumed more and more processed food, which has increased the number of genetic mutations with each successive generation. In other words, each generation has a weaker constitution and more inherent health problems. No doubt insulin resistance is one of those problems, and more and more children are exhibiting this earlier and earlier. If children, already saddled with this, try dieting, i.e. consuming low-fat food and beverages, or more polyunsaturated fats, as has been recommended over the years, their weight will increase that much more. Such was my problem growing up and all through my life. Many of the "not yet fat" children will start to get fat later in life, and these days it's the minority who remain non-insulin resistant. Of those, many will end up with cancer, so the number of thin people making it to old age is getting sparse.

To some extent, I agree with this article from personal experience. I think that dieting, particularly at a young age, can distort people's relationships with food and cause eating disorders which can ultimately lead to weight gain. Dieting can also mess up leptin and other chemicals in the body which can lead to weight gain.

However, I do think it is important that we note the following from a different page on the same website that published this article:

Tech Central Station is supported by sponsoring corporations that share our faith in technology and free markets. Smart application of technology - combined with pro free market, science-based public policy - has the ability to help us solve many of the world's problems, and so we are grateful to AT&T, Avue Technologies, The Coca-Cola Company, ExxonMobil, General Motors Corporation, Intel, McDonalds, Merck, Microsoft, Nasdaq, PhRMA, and Qualcomm for their support. All of these corporations are industry leaders that have made great strides in using technology for our betterment, and we are proud to have them as sponsors. However, the opinions expressed on these pages are solely those of the writers and not necessarily of any corporation or other organization.

(Red added by me for emphasis.)

http://www.techcentralstation.com/about.html

This doesn't necessarily mean that there findings are not accurate -- we accept findings from the Atkins people that they fund -- but we do need to be a little more careful in evaluating this research. As I said, I instinctually believe there is some truth to it, but the fact that there are no footnotes makes me a little suspicious.

"The propensity to obesity is, to a significant extent, genetically determined,"

I agree with this statement only in the context of junk diets, diets made up mostly of food unsuitable for human consumption. People's bodies react differently to different allergens and poisons. Of course, as Twighlight Z said, there is no discussion of this in the article.

There is fair evidence that a suffiently low-carb diet (one that very closely mimics the effects of our almost carnivorous forebearers) cures obesity no matter what the genetic background. Case in point is the Donaldson eskimo style meat-only diet diet, in which the only participants who failed to lose their extra weight were those who quit the diet.

I generally find this Sandy Szwarc very astute. But I have a little trouble with this idea of "it's all genetics". For a recent project, I was looking at a lot of photos from the eartly 1900's.

It struck me that in virtually ALL of the street and crowd scenes there were VERY few overweight people -- even among the well-heeled. In fact, it seemed that virtuall EVERY male seemed to weigh about 165 pounds. They are surprisingly uniform. Women seemed to be a tad heavier than today, but again virtually everyone seemed to be much the same weight.

Sort of like what you see when looking at herds of zebras, or the squirrels in the backyard. There aren't any fat ones, OR skinny ones.

If it's all genetics -- and what you eat doesn't matter -- how come we're so fat now? Did our genetics change?

Exactly! If it's "all genetics" why is there an increase in obesity over the last few decades?

I think it could be genetics. There are so many variables in who becomes fat and who doesn't. The things that are the constants are: Physical activity is falling, easily available calories are rising. Still, in the face of this, some people remain thin. Is it that they are eating differently and exercising more? Well some do, but a lot don't. They simply don't get fat.

Now the genetic oddity might be the person who remains thin rather than the fatter person.

I completely buy the idea that there is a genetic predisposition to become obese WHEN EATING A HIGH CARB DIET. Their lack of correlations in these studies, only indicates that there are a variety of ways to eat high carb, and they are all similar in their results. I would bet that not many of their test subjects were eating low carb. Kids' eating patterns are not generally predisposed to low carb.

They were surprised to see that the junk carbs had the same effects as healthy carbs. I don't think any of US are surprised by that though.

Well if children who dieted gained significantally mor weight than the ones who never dieted, it is probably because the ones who never dieted didnt need to diet.

I recently found my high school yearbook from the mid-1970s and there were virtually no fat kids in any of the pictures. No wonder I felt huge, even though I was probably about 10 or 15 pounds overweight. Looking at my picture in the yearbook, compared to today's high school students I would not look overweight at all. Compared to my contemporaries, I definitely was.

I think that the tendency to gain weight is genetic -- and some of us have always been heavier than others (like I just described myself in high school) -- but our environment has interacted with genetics to cause a problem. I don't believe that anyone's genetics makes them morbidly obese. Genetics could result in someone being 10 or 15 pounds overweight -- I was very active in high school and I ate well so I can attribute that moderate amount of overweight to genetics -- but it takes a toxic environment to get an epidemic of obesity.