Fat land : how Americans became the fattest people in the world (12 page)

Then, just as both groups prepared to announce the new test, the council, led by Hayes, threw up a new barrier: the body composition test. It was, he said, "inappropriate." It might hurt kids' feelings. And it might make parents mad that someone was touching their child. Anyway, Hayes said, the council "wasn't ever in the business of making weight an issue."

But for the council, such opposition to the "weight issue" was

FAT LAND

something new. Ever since its founding, body weight had been a key element of its agenda. The council's theme song, after all, had been quite explicit about the goal of exercise — "Go You Chicken Fat Go!" In the 1970s the council had further focused on the issue of body weight and health by sponsoring a highly visible ad campaign, designed by Young and Rubicam and placed in leading general interest magazines. In one ad depicting a chubby boy eating an ice cream and surrounded by TVs, radios, telescopes, and model airplanes — symbols of sedentary behavior — the copy read: "We're so overdeveloped we're underdeveloped." Another showed a giant marshmallow and declared "Hey kid! If you see yourself in this picture, you need help," only to go on to say, "There's a little marshmallow in all of us. A little blob. A little cream puff. A little jelly belly." Another simply proclaimed: "There's no such thing as stylishly stout."

Although these were certainly not the way to approach the issue now, the reformers, led by Cooper and Corbin, insisted that weight was now even more relevant to health. There was a direct and well-documented link between excess body fat and all manner of heart disease, not to mention various bone and endocrine disorders. Knowing one's body composition was key to knowing how healthy one was and what one had to do to become healthier. "As we saw it — and as we presented it — body fat testing was no different than, say, getting a mammogram or a prostate exam," Corbin recalls. "What test isn't a little embarrassing?"

To this Hayes's allies countered with what was — for them, at least — an unlikely refrain. Putting too much emphasis on body weight, they said, could inadvertently promote anorexia. In an era when the disease had become a talk show staple, with fashion advertising the leading enemy, it was an emotional and effective debate tactic. But it was also scientifically dubious. Even the most generous epidemiological estimates put anorexia far down on the list of mainstream teenage woes.

By April 1986, when the two sides were to meet at the AAHPERD annual meeting, what was once a relatively collegial

WHY THE CALORIES STAYED ON OUR BODIES

process had broken down. The council and its supporters had come out against the skinfold test and for inclusion of the shuttle run — two decisions the reformers could not abide. "We were basically shut out," Corbin recalls. "The council showed up and began handing out copies of the printed test, with our name on it! We never got a chance to present the new test." Cooper was furious. Learning of the shutout, he walked out of the conference, taking the Fitnessgram with him. As Corbin saw it: "We blew a great chance to put parents on notice that body composition should be one thing they ought to consider when they assess their kids' health."

And they had blown it during a decade when the caloric environment for children was growing ever more toxic.

Hayes and the old guard may have been wrong about the body fat test, but on the subject of health-based exercise prescriptions they may have been more on target than many in today's fitness establishment would like to admit. If their fear that expecting less from children would lead to diminished caloric expenditure — in effect a tacit endorsement of sloth — such a fear was arguably even more justified when it came to a new set of exercise recommendations for adults that began appearing in the early 1990s, at exactly the time when sedentary behavior was at an all-time high and supersized portions and snacking became the norm.

To understand how radical the new recommendations were, consider what had been the standard "exercise Rx" prior to the 1990s. Until then, almost every organization that was in the business of making public health recommendations agreed on several things. One, that exercise should consist of sustained activity — "15-60 minutes of continuous aerobic activity," at least three to five days a week, as the American College of Sports Medicine (ACSM) put it in its formal 1978 position paper. Implicit in this was a key assumption: that the more one exercised, the more benefits one got from that exercise. This the experts called the "dose-response effect." The second point of accord related to exercise

FAT LAND

intensity. To be effective, exercise should be moderate to vigorous, with a Vmax2 — maximum oxygen uptake — of 50 to 85, with a preference for the upper end. As J. N. Morris, the reigning dean of exercise physiology, put it in 1980, "Adequate exercise means vigorous exercise."

But all through the 1980s, exercise levels among adults, which had been on the rise since the 1960s, began to plateau, then to fall. Experts attributed this to the modern lifestyle. Americans were working more hours, spending more time commuting, and, increasingly, working jobs that were not "sweat-friendly." The new American worker toiled not in a factory or even a giant corporation, but, rather, in the rising field of professional services. They had to dress nicely, or at least semi-nicely. They hardly had the time to change, exercise, shower, and get back to their desks at lunchtime. Or so the experts said.

Of course, there was another way to look at the American worker, and that was as a person with an increasingly flexible, project-oriented job. Certainly the personal computer had created vast new groups of people who telecommuted, worked from home, or — especially in the enterprising 1980s, when new business formation was at an all-time high — actually struck out on their own. One thing was certain: The typical American worker still had time for four hours of television every night.

Nevertheless, confronted with declining exercise numbers and alarming rates of cardiovascular disease, public health officials felt that something had to be done about the traditional exercise recommendations. Studies had shown that adults, like children, reacted badly to high expectations. In this view, the plateauing of their exercise rates was one big "why bother?" As in the field of physical education, a new consensus emerged among America's leading adult exercise scholars. It was time to "be more realistic" about exercise prescriptions.

Like Cooper and Corbin, these reformers — many of them using data from Cooper's own studies of adults who came to his clinic — had new science on their side. Big studies were showing

WHY THE CALORIES STAYED ON OUR BODIES

two interesting trends that supported their views. One, that moderate, not vigorous, activity was key to reducing major health risks like heart attack and stroke. And two, that total accumulated caloric expenditure was just as good as sustained continuous exercise when it came to reducing risk of heart attack, stroke, hypertension, and a wide range of chronic diseases. On both these accounts, the two most important studies — one of Harvard alumni, the other of white business executives who had come to Cooper's Aerobics Institute for fitness consultation — agreed.

In the Harvard study, men who had the highest total number of minutes of daily activity — walking to work, taking the stairs instead of the elevator, participating in light sports like bowling and gardening — also tended to have the lowest rates of these diseases. (In fact — and this would tickle many a fat boy who hated sports in school — ex-varsity athletes retained a lower-risk profile only if they maintained a high physical activity rate as an adult.) From the point of view of public policy — and of people who wanted a more palatable exercise prescription — the Harvard study provided two key debating points. The first was this: The biggest improvements in health risk reduction occurred not at the higher end of the activity curve, but at the lower — in other words, not among alums who expended, say, 5000 calories a week, but among those who exercised off 1000 calories a week. (Those who expended fewer than 500 calories a week still carried the highest risk.) The second observation was quiet, but, in a way, revolutionary. In the past experts had believed that exercise and fitness were linked in a dose-response effect — more exercise meant more fitness — but the Harvard study showed a leveling-off effect. After about 2500 calories of activity per week, the reduction in risk from heart attack didn't continue to fall. "If there is a causal relationship," its authors concluded, "the figure depicts a plateau of benefit rather than a continuing gradient benefit." If you are trying to reduce your risk of heart attack — and only that — expending more than 2500 calories a week on mod-

FAT LAND

erate exercise is a waste of time. In fact, if you are sedentary, you can reduce risk with much less exercise than you thought you could. As the Stanford cardiology professor Robert DeBusk would conclude in a separate 1990 paper in the influential American Journal of Cardiology: "High intensity exercise affords little additional benefit."

The Cooper studies provided the reformers with more ammo. Looking at the treadmill tests of 13,000 largely upper-middle-class white men and women, researchers were able to pinpoint exactly where the greatest health benefits, or risk reductions, occurred. Once again, it was at the low end. People who exercised just a little more than people who didn't exercise at all got a bigger percentage reduction in health risks than did people who were already exercising moderately and who then began exercising vigorously. "A brisk walk of 30-60 minutes a day will be sufficient," the authors concluded.

A brisk walk of 30 to 60 minutes a day, however, was still challenging to most Americans. But now two key terms — moderate and cumulative — took on a life of their own. Increasingly, as medical and professional organizations revised their standards to "be more realistic," and as the government began funding studies of "user-friendly" (read: easier) exercise prescriptions, such organizations looked not to the initial recommendations of the Harvard and Cooper authors. Instead, they looked to the key revelations of those studies — or, rather, to their own institutional interpretation of those revelations.

The American Heart Association was the first to jump on the bandwagon. In a lengthy 1990 special report, it downplayed its old recommendations of 2000+ calories a week and instead called for a minimum of "700 calories a week on three or more nonconsecutive days." Walking, the authors advised, "appears to be just as beneficial as more vigorous activities." And more: "Some benefit is apparently derived from as little as 20 minutes of low-intensity exercise three times a week." They then went out of their way to denigrate more vigorous activity, saying simply

WHY THE CALORIES STAYED ON OUR BODIES

that "there is no evidence of a health benefit at more than 2000 calories a week."

This was a slightly different line than the evidence suggested, but now intellectual parricide — not scientific precision — drove the effort. Morris be damned. Vigor be damned. Even the authors of the Cooper and Harvard studies joined in, in 1992 proclaiming that "the response to exercise training is primarily, if not exclusively, dependent upon the total energy expended in exercise and not intensity."

Enter now the American College of Sports Medicine. For years it had cagily viewed the reform movement, only slowly lowering its Vmax2 recommendations from 70 to 50 in 1986, and then to 40-60 in 1991. During that time the ACSM's composition had changed; more and more of its most vocal members were not people primarily concerned with exercise as a way to better one's performance in everyday life — the foxhole-digging, window-hanging cadres of the postwar period — but rather scholars who were mainly interested in reducing the risk of chronic diseases, particularly heart disease. In 1993 they seized control, and in a bold and highly publicized paper issued a new exercise manifesto. Backed by the CDC, they issued the following statement: "Every American adult should accumulate 30 minutes or more of moderate intensity physical activity over the course of most days of the week . . . Activities that can contribute to the 30-minute total include walking upstairs (instead of taking the elevator), gardening, raking leaves, dancing, and walking part or all of the way to or from work . . . One specific way is to walk two miles briskly."

This, of course, was a far cry from Morris's old "adequate exercise means vigorous exercise." But it was also a long trek from the reformers' original recommendation of 30 to 60 minutes a day of brisk walking. And it hardly grew from a sense of scientific certainty. After all, only six months before, one of the CDC-ACSM panel's most influential members, Stanford's Ralph Paffen-barger, Jr., had concluded that "what kinds of physical activity

FAT LAND

should be prescribed, how much, how intense, and for whom if optimal health and longevity are to be achieved [emphasis mine] remain unanswered questions that require further clarification."

What had happened? For one, the CDC, as one panel member recalls, "was under tremendous pressure to come up with more palatable recommendations." Behind this was the surgeon general's own Healthy People 2000 Initiative, which had set ambitious public health goals but had little in the way to measure any progress toward such goals. A new set of recommendations was critical to the initiative's success, or at least its bureaucratic success. If one defined minimum fitness too high — if one set the bar so as automatically to make the majority of Americans appear too sedentary — how could there be even the possibility of success by millennium's end, when the surgeon general hoped to have dramatically changed American health habits?

The other force majeure lay in the new consensus among the ACSM majority. Many of these men and women had spent the better part of their academic lives studying what they called "exercise compliance" — how, why, and under what circumstances people tended to stick with a regimen. Although these studies tended to focus on specific (and often very small) high-risk groups, their conclusions were nearly unanimous: People tended to stick with regimens that they did not see as overly demanding. In short, the issuers of the new doctrine of "moderate, accumulated" activity believed that the average American would react to their new standards with one great "Wow! I can do that!"