On Wednesday, a congressional hearing will take up the new, proposed U.S. Dietary Guidelines, a process that has always been political, but perhaps never more so than it is now.

The guidelines affect everything from food labeling to school lunch menus to advice given by doctors. Every five years, the federal government reviews the guidelines, but as food has become a kind of political totem, with debates over “factory farming,” the marketing of unhealthful foods, and corporate food marketing, these dietary regulations have become a source of controversy.

To get an idea of just how controversial the guidelines have become, consider that five years ago, the last time they were reviewed, they received about 2,000 public comments. This year, they have received 29,000. And the uproar from various industry groups has been loud enough to get Congress to consider whether to withhold appropriations for the issuance of the guidelines.

Big Food lobbies

The proposed guidelines, a 570-page report, were authored by the Dietary Guidelines Advisory Committee, an independent group of 14 appointed doctors and scientists, working under the auspices of the departments of Agriculture and Health and Human Services. The report’s basic advice might sound innocuous enough: the American diet, according to the committee’s report, should be high in fruits, vegetables, whole grains, seafood, nuts, and legumes, moderate in low-fat dairy products, low in red and processed meat, and very low in sugar and refined grains.

There are many areas of disagreement and debate, but the main argument this time concerns the basic makeup of our collective diet. Big Food has lobbied hard to make sure that the guidelines characterize its various products as positively as possible, or at least not too negatively. Meat producers are surely happy about recent trends like the Paleo Diet, and research that has tended to counter some of the scarier scientific pronouncements of previous decades. But the meat lobby was upset that the committee’s report calls for diets that are “lower in red and processed meats.” The guidelines also urge Americans to consider eating more vegetables as a way to help the environment. The North American Meat Institute was so upset it created a Change.org petition, Hands Off My Hot Dog.

 

The sugar lobby also has protested the proposal that added sugars be kept below 10% of daily caloric intake. The Sugar Association wrote a letter to the committee asserting flatly that there is “not a preponderance of scientific evidence for conclusion statements that link ‘added sugars’ intake to serious disease or negative health outcomes…”

The Dietary Guidelines Advisory panel also had suggested a tax on sugary drinks and snacks in order to improve people’s eating habits — which angered beverage companies.

Criticism of ‘outdated science’

Adding fuel to the fire, last month an article was published by the medical journal The BMJ, charging that the advisory panel behind the guidelines based them on outdated science, and are too critical of high-fat, low-carbohydrate diets. The article — presented as an “investigation” of the advisory panel — was written by Nina Teicholz, a journalist and author of “The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet.” At the heart of Teicholz’s argument is that the panel omitted research that shows saturated fats aren’t as bad as once thought and that a low-carb diet might be beneficial; the writer argues in her piece that there is “a reluctance by the committee behind the report to consider any evidence that contradicts the last 35 years of nutritional advice.”

The article drew a lot of heat, including from Marion Nestle, a well-known nutritionist and author of “Food Politics” and “What to Eat.” While Nestle agrees that the advisory committee should be driven entirely by science and fact, she wrote on her blog:

What troubles me about Teicholz’s work is the certainty with which she presents her ideas. She comes across as utterly convinced she is right, even in the face of substantial and substantive criticism of her statements and interpretations.

Such criticism has come from the likes of Rosemary Stanton and Tim Crowe, a pair of nutritionists in Australia, who wrote a scathing response to Teicholz’s article. They addressed Teicholz’s charge that the panel was influenced by the food industry with similar charges against her (and they noted that she has an interest in selling her book.)

In terms of substance, they maintained that the advisory panel did, in fact, take recent research into account, but gave it the weight it deserves. On low-carb, they argued that there simply isn’t enough research, at least not yet, to strongly recommend such a diet. And, they wrote, the panel did address research indicating that saturated fats might not be so bad. But the committee, they said, emphasized which foods people replace saturated fats with:

The best evidence still points out that when saturated fats are replaced with polyunsaturated fats, cholesterol levels improve and the risk of cardiovascular disease declines. But the key is where these polyunsaturated fats come from; getting them from deep-fried foods or snack foods, for instance, won’t improve heart health.

The problem, the nutritionists wrote, is that too many researchers and pundits are too focused on isolated nutrients and not focused enough on the sources of those nutrients. “The food sources for fats or carbohydrates matter; talking in broad terms of these macronutrients fails to distinguish between healthy foods and junk foods. The main thrust of the advisory committee’s report is that diets should be focused on whole foods, not specific nutrients. And that makes a lot of sense.”

Members of Congress will now decide whether it makes a lot of sense to them.