TCS Daily

Killing Turkeys Causes Winter

By Sandy Szwarc - October 22, 2003 12:00 AM

Fast food restaurants have grown as have our girths, therefore fast food restaurants have caused the obesity epidemic -- or so goes the legal argument of John Banzhaf, veteran attorney for the big tobacco settlements who's now targeting another very visible and lucrative industry: food.


Plenty of things that have increased in popularity over recent decades -- natural fiber clothing, running shoes and soccer to name a few -- but it would be nonsensical to say any of these have caused obesity. Association never proves causation, any more than killing turkeys causes winter.


Yet Banzhaf's case against fast food relies upon multiple associations.


He says on his website, "obesity and obesity-related diseases occurred suddenly within the past 15 to 20 years." During those years, fast foods have become industry giants. "Fast food companies are responsible for more than 65% of the rise in American obesity and for more than $50 billion of the annual health care costs obesity imposes on taxpayers, according to a new study for the National Bureau of Economic Statistics (NBES)," states Banzhaf. "It is only fair to hold them liable for their fair share, especially since that share can now be estimated." But he goes further: "Since obese people tend to eat at fast food restaurants more often than the average American, fast foods may be more than 70% or even 75% responsible for their weight problems."


Food = Cigarettes?


Obesity is an enormously complicated issue and there is little solid evidence and no consensus among the scientific community as to what's causing it, what to do about it or even if it's a significant problem at all. William Dietz, MD, PhD, director of the Division of Nutrition and Physical Activity in the Center for Chronic Disease Prevention and Health Promotion at the CDC, told audiences at a recent obesity conference that while shifts in food practices such as more restaurant eating, fewer family meals, more products in markets, fast foods and increasing portion sizes have been implicated, "evidence linking any of these to obesity is slim." In fact, food may not be responsible at all.


An extensive and irrefutable body of evidence has proven our genes, for example, to be responsible for 50 to 90 percent of our fatness. Then there's activity levels, the metabolic changes that occur with dieting, stress, and a host of other significant factors, that leave little room to implicate fast foods.


Despite the absence of a proven smoking gun, scientists are in agreement about the risks associated with smoking: doubling our risk of heart attacks and precipitating one-third of all cancers. (Doll and Peto, 1982). Banzhaf is patterning his fat lawsuits after those against tobacco companies but unlike cigarettes, food is essential for life. Even fat and sugar are part of a healthful diet and haven't been shown to cause obesity. "Trying to determine THE "calorie culprits" in anyone's weight gain is next to impossible," said Glenn Gaesser, Ph.D., associate professor of exercise physiology at the University of Virginia and a Fellow of the American College of Sports Medicine. Plus, "the correlations between smoking and disease are vastly more compelling than the correlations between increased weight and whatever. For example, a heavy smoker has a 3000% increased risk of lung cancer in comparison to a non-smoker, while an "overweight" woman has a 13% increased risk of post-menopausal breast cancer in comparison to an "ideal weight" woman.... To treat these two correlations as being of similar probative significance is beyond absurd, but that's exactly what Banzhaf and crew are doing," said Paul Campos, professor of law at the University of Colorado.


Claim #1: Obesity is a new health crisis


Despite Banzhaf's assertions that obesity is a new health crisis, increasing weights are nothing new. As Richard Klein chronicled in his book, Eat Fat (Vintage Books, 1996), fatness is often a cultural trend with cycles of fat and thin occurring throughout history. Typically people get fatter -- and healthier -- during times of prosperity. Weights have steadily increased for the past 120 years. So have heights. If you've ever had to duck entering the homes of early Americans or tried to fit into a piece of vintage clothing you know first hand the truth in that. In the past century people in industrialized nations have grown taller by about 4 inches on average. In Holland, in just four generations the average height for men grew 8 inches. (Burns, 1998; DeGregori, 2003) But, there have been no frantic cries about an epidemic of tallness!


However an obesity crisis has been declared. We're told two-thirds of us are fat and nearly one-third obese. As sensational stories saturate the press about the need for gargantuan caskets, special medical equipment for 700 pound patients, and heavy duty furniture for 500 pounders, the reality is less than 2% of the population actually weighs 300 or more pounds, Campos estimates. And CDC data show only 4.7% have BMIs over 40. Putting the crisis further into perspective:


·         Women with a BMI of 40 have longer life expectancies than "normal" weight men.


·          While getting larger, our lifespans have doubled, going from 47.3 years in 1900 to 77.2 years in 2001, according to the National Center for Health Statistics CDC 2003 annual report. That's an incredible increase of about 4 months a year!


·         Increasing body weights during the 1990s, while statistically resulting in a national 61% increase in obesity, haven't been a health crisis for individuals whose weights have actually increased on average a mere 7 to 10 pounds, according to research by Jeffrey M. Friedman, M.D., Ph.D., at Rockefeller University.


Claim #2: The NBES study found fast food responsible for more than 65% of obesity


The singular NBES study Banzhaf uses as proof of fast food's role was a working paper created for a private economic organization, not a published work in a peer reviewed journal, and its results have yet to be replicated. It suffered from methodological problems trying to pull together data from a variety of sources produced for different purposes. Researchers Chou, Grossman and Saffer created a statistical model from one source to predict the actual weights and heights from another source utilizing self-reported data.


Putting a price tag on fast food's role is a new pursuit of limited usefulness other than being necessary before lawyers can extract settlements. You can profile most any behavior or demographic and determine how much it "costs." Indeed, another NBES study on obesity just three months earlier had concluded "sixty percent may be due to demand factors such as declining physical activity from technological changes."


But most significant, the study by Chou and colleagues did not even find that fast-food restaurants caused obesity. In fact, the researchers concluded with a cautionary note about identifying "fast food outlets as the culprits in the obesity epidemic," stating: "fast-food or convenience meals should rightly be considered as much an effect as a cause in American eating patterns." Their interpretation of their findings was that because we're working longer hours, more women have had to join the workforce, and we're struggling with depressed wages and little real gains in income, the food industry has merely met consumer demand for fast and inexpensive foods. The longer working hours have also reduced leisure time available for increased physical activity.


In a review of economic research on obesity, Alexander Tabarrok noted another result of the NBES study that we're unlikely to hear from Banzhaf: "obesity has increased in places where taxes and other interventions have raised the price of cigarettes." It's well known that individuals who quit smoking tend to gain weight -- so the legal actions against Big Tobacco that Banzhaf takes credit for could be said to share the blame for rising obesity.


Claim #3: Obese people eat more fast food than other Americans


Blaming fast food, or any food, thinly veils a condemnation of fat people as gluttons. "There is very little evidence that fat people eat more fast food than thin people," said Paul Ernsberger, Ph.D., associate professor of Medicine, Pharmacology and Neuroscience, Case Western Reserve School of Medicine. In fact, "most people eating fast food are thin... Marketing studies show that the typical frequent fast food buyer is a young single male, a relatively thin demographic group. Middle aged women are the fattest demographic and eat little fast food. Most obese people are dieters. Dieters do not eat fast food very often," he said.


Bachelors eat the most fast food, followed by families with preschool to grade school children, according to Ernsberger. But as a comprehensive review of childhood obesity by the Center for Weight and Health, University of California Berkeley documented, "consumption of high-calorie, low-nutrient-dense foods has been observed to be high among children and adolescents, regardless of weight status." (Ritchie, etal, 2001) In other words, just as many thin as fat kids eat junk food.


Observing fast food restaurants at lunchtime, you're most likely to conclude that eating fast food will make you a skinny construction worker. In poor, inner city neighborhoods, fast foods are often the only types of restaurants available. Targeting fast food for higher taxes or regulatory costs would primarily penalize the working poor and do nothing for obesity.


Just because fast food is more prevalent in poor areas, and the poor have higher rates of obesity, does not mean that fast food caused their obesity. Multiple researchers are finding that poverty may be the result of obesity. Research by Esther Rothblum, a psychology professor at the University of Vermont, has concluded that being fat makes people "downwardly mobile," because of obstacles they face to education, work and marriage. Other researchers believe the stress of poverty raises cortisol levels, a stress hormone which promotes fat storage and makes you fat. As a recent National Post article noted, when rich kids and poor kids eat exactly the same diet -- be it burgers and fries or tofu and sprouts -- the poor kids get fatter. The Berkeley report outlined a number of other poverty-linked contributors to obesity such as low birth weight and prenatal factors, and noted "low SES may be a risk factor for overweight among children as young as preschool age."


Obesity is complex and the simplistic blame of fast food doesn't explain the underlying causes. "If every McDonald's closed tomorrow, there is no evidence that anyone would lose weight," said Ernsberger.    


Additional references

Burns, Susan. Why are we getting taller as a species? Scientific; June 29, 1998.


DeGregori, Thomas R. Modern diets start helping in the Womb. American Council on Science and Health. Health Facts and Fears; July 17, 2003.


Doll, Richard and Peto, Richard. The Causes of Cancer: Quantitative Estimates of Avoidable Risks of Cancer in the United States Today. Journal of the National Cancer Institute; 1982; 66: 1191-1308.


Ritchie, Lorrene etal. Pediatric Overweight: A Review of the Literature. California Dept of Health Services Childhood Obesity Prevention Initiative, June 2001.


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