The scenario is so common it ought to be a cliche. Some batch of scientists comes up with a study that suggests something about weight loss and nutrition in humans. A bunch of mostly ill informed journalists misunderstand the findings and write them up with misleading headlines. Then someone shits out a book with a catchy title, and before you know it a new diet craze or exercise fad has been born.
The life cycle of a diet Americanus is the main subject of Susan Yager’s book “The Hundred Year Diet: American’s Voracious Appetite for Losing Weight”. Starting early in the last century, the idea that it was unhealthy and unattractive to sport more than the bare minimum of lipids on one’s person took hold of the American consciousness. The country has been on a diet ever since and Yager’s book is as close to a comprehensive chronicle of that history as you’re ever likely to find.
For example, in a sentence that could have spewed forth from the laziest politician or pundit any time in this or last century with hardly a modification, in 1952 the American Medical Association announced (with grand, anti-Communist panache) that “Overweight among American business executives is threatening destruction of the nation’s productive capacity and free enterprise system.” Similar warnings have been sounded for any number of reasons ranging from military readiness to economic competitiveness, our current “obesity epidemic” is just the latest iteration.
In Chicago in 1920, the city health commissioner recruited twenty-five overweight women to get thin. It was such a successful media circus that, not to be outdone, a female newspaper columnist recruited twenty-five men for the same public shaming. A similar contest was then held in New York City, this time with fifty participants of each gender. Thirty years later, Bonnie Prudden, who died earlier this month at the age of 97, rose to fame and started an exercise hysteria by declaring that America’s kids were failing basic physical fitness. Her report came out in 1955, in what we now think of as the halcyon days of neighborhood kids playing outdoors all day.
You can look back to literally any period of American history since the rise of scientific medicine and industrial food production and find a panic over national obesity. Even nine decades ago there was already a rich history of fads and fanatics peddling ways to “reduce”.
As a result the book does suffer from an almost hyperactive need to jump from one topic to the next. Not only are the chapters extremely short, sections within chapters are sometimes little more than a few paragraphs. Diet fads and equipment, along with the names of their clever creators, are listed at a breathless pace, but little is done to tie them together or situate them in the overall picture of dieting in America.
That’s simply the unavoidable result of the fact that America has, for more than a century now, been awash in ways to reduce. For every pill and supplement there’s a lunatic contraption that claims to help you exercise while you sit on your ass. Every contorted diet plan that demonizes some foods and lavishes praise on others has a doppelganger that reverses the emphasis and promises the same wondrous results. The silver lining to that quick pace and lengthy list is that when you look at all of them together like that the absurdity is more apparent than a supermodel’s rib cage. Things that can sort of seem plausible if taken on their own are revealed to be variations on wild quackery.
Unfortunately, despite the entertaining and exhaustive catalog of fads and fopperies, The Hundred Year Diet shortchanges some of its own conclusions. Specifically, there are two concepts which surely deserve a bigger mention than the relatively brief ones they get in the book. The first is the way weighing less is something that will always be extra difficult and bordering on impossible for some segment of the population. The second is the still primitive nature of our understanding of how nutrition affects individuals.
The former point is one that Yager can’t bring herself to gloss over entirely, but it’s clearly something she doesn’t like bringing up. Yes, it’s true that as a population we are much heavier than we used to be, and it’s true that there are a great deal of negative health consequences associated with that. One need look no further than the expensive and potentially debilitating effects of our high rates of Type II Diabetes to see that.
But some percentage of the population, for reasons ranging from genetics and conditions in utero to levels of gut bacteria and who knows what else, simply cannot lose weight the same way most of the population can. This is closely linked to the ugly cultural realities of being less than twiggy in America, in everything from social shaming to reduced earnings and job opportunities. There aren’t a lot of Americans who think to themselves, “I’ll get that better job/person-to-sleep-with if I just start eating more Oreos”, whoever wants to be the next fat guy on Saturday Night Live obviously excepted.
The sad fact is that we still don’t have a way to identify people who can carry extra pounds safely from those who can’t, nor do we have a way to differentiate those who can’t lose weight from those who simply eat too much and don’t get enough exercise. While we can say with great confidence that most people will lose weight if they develop better exercise and eating habits, there isn’t a reliable way to know what specific tactics will work better for one person or another. Even something as seemingly simple as understanding what causes one person’s metabolism to speed while similar diet and behavior cause another’s to slow remains mostly beyond our grasp.
Nor are the limits of our nutritional knowledge restricted to being baffled by the differences between how much weight one person gains versus another on the same diet. Even calorie counts, those seemingly solid numbers which are the sacred bane of dieters from coast to coast, are probably wildly off the mark (via). The realization of the paltriness of our understanding is disconcerting in a lot of ways. Even people who don’t exercise and eat right are usually confident that if they start, those numbers will guide them along the way.
But what’s clear based on more than a century of “scientific” diets, different ways to measure people, and slick quackery all aimed at slimming people down is that numbers are overrated. For a society that runs on numbers that is a confusingly counterintuitive conclusion. After all, we use numbers to track everything from money to yards after catch. The computers we spend huge chunks of time using are basically just big collections of ones and zeros. Hell, counting is practically the first thing we teach to our blank slate offspring.
Translating that fetish for numbers into the realm of weight loss and nutrition seems natural as can be. You can buy fancy electronic scales that will measure your weight and body fat down to a decimal place, but in doing so we overlook how poor our data is, how fat the error margins on our instruments, how little will still know about the genetic differences between individuals and their interactions with their environments. It looks smooth and modern and reliable, but a quick glance at a century of history of diets and reducing makes a hollow mockery of that idea.
Given that all those unknowns fit smoothly into Yager’s general point that diet fads are about as scientific as other fads, it’s a shame she doesn’t engage them more. All those specific numbers, be they weight, BMI, or calorie counts, are all but useless information. Calorie counts are notoriously inaccurate and the BMI scale is likely skewed such that some purportedly healthy BMIs are associated with more health problems than some heavy ones considered unhealthy.
Most disastrous for mental and physical well being, however, is the relentless focus on weight in pounds. It’s a number almost everyone knows about themselves, and yet it’s far too specific for the kind of day-to-day self regulation most people need. Gaining or dropping ten pounds is, from a health point of view, almost always meaningless, and yet we’re constantly inventing new ways to track ourselves down to a tenth of a pound. No wonder the country is always on a diet.
Smart phones and internet sites that track your diet and training are just the latest incarnation of yesteryear’s contraptions and systems. When we pretend that the “science” of twenty or forty years ago is laughable while ours is advanced we ignore the fact that twenty or forty years from now people will think our science is only marginally less primitive than we do theirs.
The reality is that we have only a very rough outline of what numbers like weight, cholesterol, and body fat mean. We have an even rougher outline of how the nitty-gritty details of our myriad biochemical processes operate. And our understanding of how those processes vary and affect individuals is so skeletal that it doesn’t even qualify as an outline. Some day you may be able to get a quick and inexpensive blood test that will analyze your genes and all those different microorganisms to which you are a host and say something like, “Eat all the pizza you want, but avoid butter like the plague and go swimming three times a week”. But we are very far from that day.
In the meantime, we can only continue to plod along with what we do know while being aware of all that we don’t. For the majority of people, eating less and exercising more will work. It may not cause you to lose enough weight to fit into unrealistic pants, it may not cause you to turn heads poolside, but it will likely make you as healthy as you can be. What you don’t want to do is torment yourself over holiday eating, make grand resolutions tied to specific numbers, or spend money on books and systems that all boil down to basically the same idea, eat less and exercise more.
End Note: As if to prove Yager’s point, a Google search for “hundred year diet” produces her book on Amazon as the #1 result. The #2 result is “The Hundred-Year DIET: Guidelines and Recipes for a Long and Vigorous Life”, yet another entry in the long quest to remain thin and healthy through poorly understood nutritional rituals.
