Quietly last month, a pair of Harvard endocrinologists published a commentary in JAMA that suggested to the authors of forthcoming new dietary guidelines that they essentially throw out nutrition altogether and start talking about food. (Unfortunately, it is available by subscription only, but the first 150 words can be found here.)
Health officials in our country revise the official dietary guidelines every five years. They are meant to help us eat well, of course, and their public face is the much-maligned Food Pyramid. For years, the criticism of the guidelines has been that they harbor an indefensible conflict of interest — they are produced by the same agency (the USDA) responsible for promoting the products of America’s farms.
The last revision of these guidelines, in 2005, came under criticism because the agency hired the PR firm Porter Novelli to help create a goofy MyPyramid graphic, and Porter Novelli is an outfit that represents some of the country’s largest food companies. MyPyramid also produced complaints that the final visual product, a stick man climbing the side of triangle with six bands of color, seemed to represent nothing. Which, if you consider the lax regulatory vibe during the Bush years, may just have been their intention.
But the architects of these guidelines didn’t need to hire the pitchmen for Campbells to undercut their message. In another society, one that had not been persuaded by a power structure determined to shift responsibility in matters of health to the individual, whether this shift be supported by science or not, they could have easily come under criticism for providing sort of a one-stop handbook for all that is wrong with how we think of food and health in our country. The guidelines present as useful the BMI chart, for instance, which is descriptive, not prescriptive. They endorse the first law of thermodynamics (calories-in, calories-out), which, as Gary Taubes argues, tells us nothing about the causality of weight gain. They endorse exercise as a weight management strategy, which is also a dubious albeit food-industry-palatable message if we are to believe the previous point.
And of course, any guidelines with densely structured registries of advisable daily intakes of protein in grams bears little connection with the food environment itself — the mundane reality of grocery stores and dinner chains and take-out. We buy food in stores — often as food products marked Lean Cuisine or Progresso or Schwann’s. As one critic describes it, the pyramid is a “peculiar icon of nutrition advice that adorns cereal boxes and not much else.” This is because the guidelines speak as if we procured food from laboratories filled with finely calibrated, food spectrometer machinery.
As David O. Ludwig and Darius Mozafarrian write in “Dietary Guidelines for the 21st Century — A Time for Food,” “few individuals can accurately gauge daily consumption of calories, fats, cholesterol, fiber, or salt.” As the pair explain, the guidelines were originally developed to combat nutritional deficiencies, health problems which no longer exist (unless you accept Taubes’ thesis that obesity is a function of carbohydrate-induced malnutrition). Then our dietary guidelines were refined during the 1970s and ’80s to address chronic diseases, though their answer — “low-fat” eating as a solution to heart disease, cancer and diabetes — proved healing for the food industry but counterproductive for public health. But check this out: In a wide-ranging condemnation of nutrient-based dietary guideline policy, the Harvard duo basically burn down the entire nutritional house.
“The proportion of total energy from fat appears largely unrelated to risk of cardiovascular disease, cancer, diabetes, or obesity. Saturated fat — targeted by nearly all nutrition-related professional organizations and governmental agencies — has little relation to heart disease within most prevailing dietary patterns. Typical recommendations to consume at least half of total energy as carbohydrates, a nutrient for which humans have no absolute requirement, conflate foods with widely divergent physiologic effects (e.g., brown rice, white bread, apples). Foods are grouped based on protein content (chicken, fish, beans, nuts) despite demonstrably different health effects. With few exceptions (e.g., omega-3 fats, trans fat, salt), individual compounds in isolation have small effects on chronic diseases. Thus, little of the information found on food labels’ “nutrition facts” panels provides useful guidance for selecting healthier foods to prevent chronic disease.”
As my mother-in-law would say, “Whoa. Back the truck up.” In order, the above paragraph can be distilled to state,
a) the percentage calories from fat in a food is meaningless,
b) the percentage of saturated fat in a food is meaningless,
c) the human body does not need to eat grains, be they whole or refined,
d) you can forget about reading the Nutrition Facts altogether.
Of course, Michael Pollan would have you stop reading Nutrition Facts statements because they accompany a food product, like Hot Pockets, rather than a food, like spinach (he prefers the latter). But this is surely the first time such a high-profile authority has recommended trash-canning the previously unkillable fatwa in medicine and nutrition against saturated fat. (Note to all mothers reaching for 1 Percent in the dairy section — it’s over.) The reason for the authors’ scorched-Earth run on the holy texts of nutritionism is that, as they see it, good health is enabled by the whole of one’s diet, not the sum of individual nutrients consumed.
“Fruits, vegetables, whole grains, and nuts are consistently associated with lower risk of disease. Fish consumption reduces risk of cardiac mortality, belying categorization with other protein sources. Conversely, processed meats, packaged and fast foods, and sugar-sweetened beverages increase chronic disease risk. The effects of foods likely reflect complex, synergistic contributions from and interactions among food structure, preparation methods, fatty acid profile, carbohydrate quality (e.g., glycemic index, fiber content), protein type, micronutrients, and phytochemicals.”
OK, so that last sentence may have lost you. But what they are saying is that the dietary path to health is not paved by counting your intake of calcium in grams, much less trying to avoid saturated fat or to organize your meals around protein and carbohydrates. The path to health is in avoiding food from the people who have, until now, been the biggest gamers of distractions like MyPyramid. The food industry.
“The nutrient-based approach may foster dietary practices that defy common sense. Countless highly processed products are now marketed in which refined carbohydrate replaces fat, providing an aura of healthiness but without actual health benefits. School nutrition guidelines specify a minimum number of total calories but a maximum proportion of fat calories, and foods like gelatin desserts and sugar-sweetened low-fat milk have been used to achieve these nutrient targets. … Taking the nutrient approach to self-serving extremes, the food industry “fortifies” highly processed foods, like refined cereals and sugar-sweetened beverages, with selected micronutrients and recharacterizes them as nutritious. These marketing ploys provide little public health benefit and could potentially produce harm.”
It seems unlikely the authors of the next set of guidelines will write anything of the sort, unfortunately. Too many parties have become invested in both the claims of the food industry and a nutrient-based approach to nutrition to allow any new guidelines advising, say, to stop buying foods sold in boxes. Not to mention one other problem. The nature of academic ideology is such that the low-saturated fat, high-carbohydrate approach to eating — its focus on nutrients conferring instant authority on those willing to memorize the minutiae — is a ship large enough that it will not turn around any time soon. Maybe the answer is to do to the next set of guidelines what we essentially did to the last ones: ignore them.