TCS Daily


The Truth About Obesity

By Sandy Szwarc - July 14, 2003 12:00 AM

In the fight against obesity, we're told: 'Being fat is simply a matter of energy balance. It's easy to lose weight, just eat 3,500 calories less than you burn and you'll lose a pound. We've become a fat nation because we're eating more than ever before, and too much fat and junk food, and not moving.'

Of course, the real message is one of blame: 'You fat slobs! You are irresponsible, lazy, gluttons. You wouldn't be fat if you just didn't eat so much (or so much fat, sugar, and junk food) and got off the couch!'

If it were only that simple.

Eighty million Americans struggling to lose weight, and millions more starving themselves to stay thin, know it's not that simple. The predominance of scientific evidence shows it isn't, either. The problem is evidence rarely breaks through the anti-fat rhetoric.

Most of the countless popular theories as to the causes of obesity simply don't honestly face the inconsistencies about diet and exercise being unrelated to rising obesity rates. They work from the assumption and intuitive rationale that eating too much and the wrong foods, and getting too little exercise, cause obesity and that dieting is the answer, without investigating alternative explanations or seeking proof in clinical studies.

All of this has built up a mythology about obesity and obese individuals and their slender counterparts that does not hold up against the evidence.

The Myths Of Obesity

Myth One: Fat folks are slugs.

Facts: Although physical inactivity is a factor in obesity, it's not the only, or most pivotal, one. The American Heart Association (AHA) in a 1996 Medical Scientific Statement said: "Although some studies suggest that obesity is associated with increased sedentary activity, particularly watching television, or with a lower resting metabolic rate, these differences have been inconsistently demonstrated. Several studies indicate that energy expenditure per kilogram is lower in obese children, but is actually similar to non-obese children when indexed to lean body mass."

The fact that weight gain is poorly associated with inactivity is evident by looking at exercise levels as body weights increased from the mid-1960s. Centers for Disease Control (CDC) data show that through the 1990s exercise activity remained unchanged -- while obesity rates climbed. Thomas Stephens, Ph.D. in a 1987 study published in Research Quarterly for Exercise and Sport found participation in regular physical activity actually gradually increased during the 1960s, 1970s, and early 1980s before leveling off. According to an April 11, 2001, Journal of the American Medical Association report of CDC data, "trends in physical activity [then] remained stable during 1990-1998."

Realistically, lifestyles for middle-class American adults haven't changed in line with bulging weights. Back in the 1960s, most Dads (or Grandpas, for younger readers) still drove to an office job each day and mowed the lawn on the weekend; Moms took care of the house with much the same appliances and modern conveniences we enjoy today: washing machines, vacuums, electric ovens; and cooked canned soups and TV dinners. Sure, more Moms work outside the home today, but that double shift also means more work and less time to enjoy traditional sedentary activities such as sewing. Who remembers their parents donning sneakers (hardly ever called athletic shoes back then) and heading to the gym everyday or putting in an hour on the treadmill? Among lower socioeconomic classes where obesity rates are the highest, manual labor remains the primary employment.

Many researchers, such as Jeffery Sobal, Ph.D., M.P.H., and Albert Stunkard, M.D., in Psychology Bulletin, have done in-depth examinations of the multiple socioeconomic factors related to weight that are outside the scope of this article, but the point here is that those overweight individuals aren't simply lazy slugs, either.

Research has also failed to show activity levels account for body weights. A 10-year epidemiological follow-up study in the International Journal of Obesity in 1993 examining National Health and Nutrition Examination Survey (NHANES-I) data from the 1970s to 1980s, found no relationship between baseline physical activity level and later weight gain among either men or women. According to Jack Wilmore, Ph.D., of Texas A&M University, writing for President's Council on Physical Fitness and Sports, some have stated that "physical activity has only a limited influence on changing body composition." Even vigorous exercise results in unsubstantial reductions in weight, although it reduces body fat. Many researchers, including Dr. Paul. J. Pacy at the Centre for Nutrition and Food Safety, School of Biological Sciences, University of Surrey, UK, have concluded that "exercise alone appears largely ineffectual regarding weight loss."

Myth Two: Fat people are gluttons.

Facts: Many fat people eat the same or less than thin and normal weight people. The Healthy Eating Index, the nation's report card on how Americans are eating, compiled by the U.S. Department of Agriculture Center for Nutrition Policy and Promotion, found little or no correlation between weight and caloric intake. Those with BMIs ("body mass index," a measure of weight relative to height currently used to categorize size) under 20 ("ideal" figures in the media) have similar calorie intakes as those greater than 30 (considered obese), as do people at all the BMIs in between.

Multiple researchers, using a variety of methodologies, in the American Journal of Clinical Nutrition and the Journal of Applied Behavioral Analysis 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.

Myth Three: Those who virtuously eat less or who diet will be slim.

Facts: This may be the biggest -- and most dangerous -- myth of all.

Weight loss diets have been around at least since the 1830s with Sylvester Graham's preaching the sins of gluttony, they started to become a national mania in the mid-1960s. Fatness had become medicalized, and a rapid succession of weight loss products ensued, from various diet pills to diets such as Atkins to full-fledged diet programs such as Weight Watchers. Weight loss measures grew extreme by the 1970s with such high protein diets as Robert Linn's liquid diet and the Complete Scarsdale Diet. By the end of that decade there were more than a hundred different diet programs, mostly hosted by doctors, and those numbers had tripled just a few years later. Today, there are literally thousands.

The diet advocates have continuously claimed that by eating less, and less fatty foods, we could all be slim. Americans listened. According to the U.S. Department of Agriculture (USDA) Center for Nutrition Policy and Promotion, total caloric intake, as well as total fat intake, steadily decreased from 1965 to 1990. During this period, obesity increased dramatically, Steven Blair, P.E.D., president of the Cooper Institute noted in a February 2002 Mayo Clinic Proceedings. "The prevalence of obesity," he concluded, "is unlikely to be due to increases in daily energy intake."

We're not the only nation to realize that weight gain can't be explained simply by how much people eat. Between 1980 and 1991, the number of heavyweights in England doubled, while Britons were eating 10 percent fewer calories, according to their government.

But American women appear to have been most affected by admonitions to watch what they eat. Before the diet mania, the average American woman took in 3,000 to 5,000 calories a day; today that average woman eats less than 1,600 calories daily and is on some type of weight loss program, according to Frances Berg, M.S., in Women Afraid to Eat -- Breaking Free in Today's Weight-Obsessed World (Healthy Weight Network, 2000).

Yet, studies published in peer-reviewed journals from researchers including R.J. Tuschl, Reinhold G. Laessle and Jane Wardle, have found that women who watch what they eat and are light eaters, or who have dieted, actually weigh more than those who don't restrict the foods they eat -- even though they're eating about 620 calories less a day! Many fat individuals have spent their lives restricting what they eat, with valiant willpower and self-control; they just don't look like it.

Indeed, after decades of decreasing fat and calorie intakes, 1990 saw a quirky dip especially in men, followed by the recent increase back to 1965 figures; but throughout this entire period, Americans kept getting fatter, while not eating any more than they had before. By the 1990s, it was clear that the low-fat and diet messages weren't working and the USDA, (AHA), and the American Dietetic Association (ADA) began moderating their recommendations, which are reflected in more recent dietary figures.

Those trying to convince us of an "obesity crisis" use a common sleight of hand in selectively using only dietary changes since 1990. By taking a narrow sampling to support their claims, these diet proponents exaggerate our bad habits and attribute them to obesity, all the while ignoring why obesity rates soared for decades when we were eating less fat and fewer calories than we are today.

Eat Less, Weigh More?

These are the facts: Medical and physiological research has demonstrated that obesity is the result of multiple factors and, as Dr. Wilmore has stated, "its etiology is not as simple or straightforward as was once believed."

Those realities, though, are hard for even some scientifically-minded folks to believe, perhaps because in the laboratory the law of thermodynamics is so simple, the solution to obesity should be, too. And the scientific community also isn't free from the weight biases that plague our culture. Fatness may be "indicative of our slovenly lack of self-discipline in an era of loose morals....those concerned for public health are within their rights to respond with the more-justifiable slogan 'fat is deadly' and even with the judgment 'fat is evil,'" wrote Todd Seavey, editor of the American Council on Science and Health's Health Facts and Fears, in a March 28, 2002, forum feature, "Issuing a Fatwar."

The scientists and diet proponents, as well as the public at large, need to confront these questions: What if it's not been food making us fat? What if we're getting fatter not because we're eating appreciably more or eating the wrong foods (or even exercising notably less), but because we've been trying to avoid those "fattening" foods? What if dieting is responsible for many of the health problems currently being attributed to fatness?

For the evidence proves a person can be doing everything right, eating properly and exercising faithfully, yet still be fat. It shows that as our obsession with thinness and the numbers of us dieting or watching what we eat have escalated over the past 40 years, so have our weights. It's time to look beyond the myths and find the real reasons why.

Part 2 coming soon: Are junk food, sugar and fat to blame for our expanding waistlines, or is it within ourselves?

© 2003 Sandy Szwarc. All rights reserved.
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1 Comment

Unabsorbed calories and physiological adaptation
Two important aspects of physiology generate confusion where weight control is concerned. First, the digestive system is not anywhere near 100 percent efficient at absorbing calories. Scientists have measured calorie excretion rates ranging up to 60 percent wastage. Consequently, no laws of thermodynamics are broken when people increase caloric intake and don't gain weight.

Second, the body adapts to variations in timing and amount of caloric intake by remodeling the digestive system or altering tissue. For example, rats fed once a day will develop larger stomach capacity and increased intestinal absorption area. Another adaptation has to do with brown fat tissue. Brown fat is metabolically active tissue that is rich in blood vessels. It burns fat generating heat to help regulate body temperature. Slender people often have more brown fat tissue than the obese who carry a lot of insulation around.

These are but a few of the physiological differences between individuals that predict how calories are both utilized and wasted.

David Brown
Nutrition Education Project

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