Let the lobbying begin. Every five years since 1980, the government releases its Dietary Guidelines for Americans. But what used to be a quiet, deliberative review of scientific evidence by experts has become a battlefield where special interests and the food industry lobby to push their agendas.
The dietary guidelines represent the government’s core advice on healthy eating. Importantly, the guidelines form the basis for much federal, state and local food policy — like the school lunch program and congregate meals for older Americans — so the stakes are high for the food industry, which has much to gain from muddying the waters.
{mosads}Many prominent attacks on the guidelines have been error-laden and misleading, including one medical journal article that needed eight corrections and clarifications. Some critics have oversimplified the science on diet and health to focus on just one question: Which is better, low-carb or low-fat diets?
Some have even gone so far as to blame America’s obesity epidemic on the guidelines, rather than on Big Food, which surrounds us with super-sized burgers, fries, shakes, pizzas, burritos, fried chicken, cheese nachos, popcorn, cookies, cupcakes, doughnuts and sodas. And not just at sit-down and fast-food restaurants but at movie theaters, shopping malls, gas stations, convenience stores and elsewhere.
One such attack was made recently in The Hill by Sarah Hallberg, medical director of Virta Health, a company that offers a pricey and proprietary low-carb treatment for Type 2 diabetes. Among the facts that Hallberg gets wrong:
The 2015 guidelines don’t advise Americans to cut back on fat
The guidelines advise limiting saturated fat, which is found largely in meats, butter, cheese, ice cream and most cupcakes, cookies, and other sweet baked goods.
Saturated fats are unhealthy
Hallberg writes that “Modern nutrition science…shows that fats, including saturated fats, aren’t unhealthy. A dozen major literature reviews demonstrate that fat intake has little to no effect on death from cardiovascular disease.” Reviews on total fat or saturated fat? Hallberg seems to conflate the two. The guidelines’ advice to replace saturated fats with unsaturated fats is backed by strong evidence recognized by the American Heart Association, the American College of Cardiology and the World Health Organization.
Low-carb diets are no magic bullet for weight loss
Hallberg asserts that “one meta-analysis published in the British Journal of Nutrition comparing low-fat diets to low-carb ones concluded that weight loss is greater with a low-carb diet.” Most meta-analyses of randomized clinical trials, as well as a recent year-long trial from Stanford University researchers, found no difference in weight loss between low-fat and low-carb diets.
Virta’s study was not a randomized controlled trial
Hallberg continues: “At Indiana University Health, I oversaw research in conjunction with Virta Health that put patients with Type 2 diabetes on a low-carb diet that severely restricted grains and pasta while increasing their consumption of fatty foods such as avocados and butter….A majority actually reversed their diabetes.” Reversed? Not quite. Though blood sugar levels dropped in the low-carb dieters, roughly 65 percent were still taking a diabetes medication called metformin when the study ended, down from 71 percent when the study started.
{mossecondads}More importantly, the study didn’t randomly assign the participants to either of two diets, so it’s impossible to know what led the low-carb dieters to lose weight and lower their blood sugar. (Hallberg failed to disclose that a majority of the study’s co-authors — Hallberg included — are employees who were offered stock options in Virta, which funded the study.)
Americans haven’t followed the guidelines
Despite Hallberg’s attempt to cast the guidelines as a stern command to simply eat less fat, its advice is more comprehensive: consume a “healthy eating pattern” that includes more fruits, vegetables, whole grains, dairy, seafood, beans and oils and less added sugar, refined grains, salt, and saturated fat. And, as the guidelines note, Americans are not meeting those goals.
You can blame Big Food, not the government’s advice, for making that so tough to do.
Bonnie F. Liebman, MS, is the director of nutrition at The Center for Science in the Public Interest, a nonprofit health advocacy group based in Washington, D.C., that focuses on nutrition and food safety policies.