After the Korean War ended in 1953, the world's doctors were taken aback by the results of the autopsies performed on America's fallen troops. More often than not, the young soldiers' hearts were riddled with fat deposits in the same places that plaques were found in middle-aged patients with cardiovascular disease. Pressed for an explanation, scientists dusted off a decades-old theory put forth by a Russian scientist that suggested cholesterol was at fault for vascular damage in rabbits. Thus the cholesterol scare was born, and to this day Western doctors continue to recommend anti-cholesterol medication to an increasing number of adult patients as a matter of course.
This case, like so many before and after it, is a testament to governments' repeated failures to get results in offering their citizens dietary guidance. Since U.S. physiologist Ancel Keys began the famous (and to some, infamous) Seven Countries Study in 1956 linking diet to coronary heart problems, officials have been slow to act. Cardiovascular disease is still the leading cause of death worldwide; of those deaths, as many as three-fourths occur in low- and middle-income countries. Though we have made significant headway in areas like reducing the use of tobacco, have we really done enough to tackle unhealthy diets and the health problems they can cause?
On Shaky Ground
Despite its importance to global health, the field of nutrition has long struggled to compete with rival specialties in medicine to attract the best and brightest or draw funding to its research. This can be explained in part by the persistent methodological hurdles blocking its success. Large dietary intervention trials, for example, can be tough to come by because of the financial and logistical costs associated with providing the study's subjects with food for the duration of the test period. Moreover, most health effects of particular diet choices don't make themselves known for many years.
Because of these issues, and many others, most nutritional scientists have to content themselves with cohort studies — the next best thing when it comes to persuasive power. These studies monitor the health of a particular population over longer periods of time, recording what lifestyle choices people make and how they ultimately fare. But even these expansive (not to mention expensive) studies are few and far between; beyond the European Union's occasional multinational study, New England institutions hold a quasi-monopoly on population-based nutritional research, a position that often tempts their scientists to extrapolate sweeping policy recommendations from results that often aren't strong enough to fully support them. This leaves policies vulnerable to criticism from other academics and food producers alike, putting the already shaky foundation of nutritional science on even less steady ground.
The Politics of Pyramids and Plates
Amid such constant controversy, it's no wonder policymakers have a hard time translating complex research results into a set of authoritative dietary guidelines that the public can easily grasp and act upon. Following the lead of the Swedish National Board of Health and Welfare, albeit 20 years later, the U.S. Department of Agriculture (USDA) published its famous Food Guide Pyramid in 1992. The diagram showed the relative importance of six different food groups by their sections' size: The largest layer included bread, cereal, rice and pasta; the second largest encompassed vegetables and fruit; the next listed dairy products such as milk, yogurt and cheese as well as proteins like meat, poultry, fish, dried beans, eggs and nuts; and the narrow top layer was reserved for fats, oils and sweets.
But vested interests interfered with the pyramid's creation. Rather than being designed by the U.S. Food and Drug Administration — the U.S. agency tasked, in its very name, with examining the safety of food and drugs — the pyramid was sponsored by the agency responsible for overseeing the farming industry. In fact, the USDA changed the order of the pyramid's levels from the one nutrition experts initially proposed in order to better correspond with the rates of subsidies Washington gave to producers in the various food groups.
It isn't clear just how big of an impact this decision had on the ongoing efforts of the World Health Organization and Food and Agriculture Organization to maintain accurate recommendations on scores of dietary factors "to prevent obesity, chronic diseases and dental caries" in the world at large. But what is clear is that many countries adapted the USDA's Food Guide Pyramid as a means of tailoring their production and acquisition of local foodstuffs and shaping their population's eating customs. (Some Asian states even went so far as to change the pyramid's shape to a pagoda in the hope of ensuring its widespread acceptance.) Though the pyramid probably had little impact on local populations' eating habits, food products themselves came under mounting pressure to conform to guidelines that reflected those the United States had put forth to boost its exports of wheat and soybeans, which then accounted for over half of the United States' total crop production.
After the Food Guide Pyramid was published, Walter Willett, the head of Harvard's Department of Nutrition, asked that the guidelines be altered. A USDA committee granted his request, provided that he disclose evidence supporting the changes he had proposed. Willett famously replied that he didn't understand the grounds for the committee's demand, since it had apparently reached its conclusions about the pyramid without the necessary evidence in the first place. More than two decades later, the committee — now staffed by more members who have been inspired by Willett's work — assembled the most solid scientific findings available to support the creation of the 2016 food guide, which by then had transformed from a pyramid to a plate.
Last year it became public knowledge that for decades the sugar industry had systematically paid researchers to steer scientific reviews in nutritional research in its favor, a practice reminiscent of the tobacco industry's age-old strategy.
Yet the political imprint made long ago had never truly faded. Last year it became public knowledge that for decades the sugar industry had systematically paid researchers to steer scientific reviews in nutritional research in its favor, a practice reminiscent of the tobacco industry's age-old strategy. This time, the food industry watched with delight as a team of counter-experts attacked the committee's guidelines, ironically, on their scientific merit, arguing that they lacked the evidentiary strength that only randomized, controlled clinical trials can provide. They overlooked the fact that such trials are notoriously difficult to conduct in nutritional science, narrowing the concept of evidence-based evaluation to research that yields only the firmest of evidence rather than, as common sense would dictate, the best of available evidence.
This intense tug-of-war has not been without consequence to society. For one, dietary guidelines developed in the more affluent corners of the world are readily copied throughout the rest of the globe, in places that lack the research capacity to tailor the guidelines to their own regional lifestyles. Though it makes little sense on its face, there really aren't many feasible alternatives to applying the results of studies done in New England to communities living on the other side of the world. Organizations often have no choice but to follow official nutritional guidelines for the sake of showing impartiality when doling out school lunches, prison meals and aid packages.
Personal Choice: The Harmful Side Effects
Despite its methodological limitations, nutritional science has given more than enough evidence to do a world of good, if only we were to put it into practice. But even that is a taller order than it might seem. A recent European study across seven different countries showed that an intense community program designed to inform parents, teachers and children about healthy lifestyles barely made a dent in individual behavior. Meanwhile, calls for governments to intervene in the spreading obesity epidemic are becoming more difficult to ignore.
To make matters worse, the rapid proliferation of dietary advice — much of which seems to be based less and less on fact — has made it tougher for people to figure out whose counsel to follow. The rise of the internet has only added to the pool of questionable suggestions on what to eat and how to eat it. Major stores and restaurants, for their part, are reluctant to offer healthier foods for fear of losing the business of customers who have grown accustomed to the ease and flavor of goods. It is no coincidence that the food industry (and the politicians it supports) are quick to argue for customers' freedom of choice and, when pushed, will only grudgingly promise to instate self-regulation to ward off government interventions as long as they can. And as fast-food chains have spread worldwide, the prospect of stemming the growing epidemic of unhealthy lifestyles and obesity has grown bleaker.
Fighting the use of tobacco was — and still is — hard. It took several decades of concerted action to weaken society's proclivity for smoking, despite a mountain of clear evidence of its harmful side effects. Fighting the unhealthy diet will be even harder, given how complicated the research results have been and that eating is a necessary part of every person's day. At this rate, stamping out unhealthy eating to the extent that smoking has been could take centuries, far longer than the lifespans of populations whose health is already in jeopardy. And while the medical burden that these lifestyle choices bring to bear will be heavy indeed for wealthier countries, it will be crippling to the rest of the world.