Guest Commentary

Are the federal government’s dietary guidelines making us fatter?

New nutritional science research is constantly emerging. Butter may not be the dietary villain many Americans think it is.
New nutritional science research is constantly emerging. Butter may not be the dietary villain many Americans think it is. Big Stock Photo

The rate of obesity in Missouri has nearly tripled since 1990. The Show-Me State is now the nation’s 10th-fattest state.

Along with obesity comes a host of health problems. Three in 10 Missourians have hypertension. One in 10 is diabetic. As of 2010, nearly 384,000 state residents had heart disease. Almost 100,000 had obesity-related cancer.

Missouri is not alone. Obesity rates, and their consequent health problems, are skyrocketing nationwide. For decades, the federal government has tried to combat this epidemic, largely through the Office of Disease Prevention and Health Promotion’s Dietary Guidelines for Americans, which aim to help people choose eating patterns that improve health.

Paradoxically, over the past two decades, Americans have continued to gain weight, despite many following the government’s dietary advice.

One might assume that no one pays any attention to the government’s guidelines, but they actually have a huge influence on how we all eat. They shape the National School Lunch Program, dictate military rations and provide advice for nursing-home meals. They also influence the doctors, nutritionists and dietitians who deliver dietary advice.

The guidelines were first released in 1980 as a simple, 20-page booklet. Today they total 144 pages, based on a larger report of 571 pages. Still, as the report has grown in length, Americans have grown in size. Thus, in 2015, Congress directed the National Academies of Science, Engineering, and Medicine to take a look at the process used to draft the guidelines. Its report found that the methods used to produce the guidelines “require increased rigor to better meet current standards of practice.”

That’s largely because new nutritional science research is constantly emerging. Saturated fat and salt offer two clear examples.

The guidelines long instructed people to eat fewer fats and more carbohydrates, so people banished butter and increased their consumption of breads and sweets. From 1970 to 2000, Americans’ average daily consumption of carbohydrates rose by 60 grams — or about 250 calories — while their fat consumption decreased.

But a number of studies now show that for many people, eating too many carbohydrates can drive weight gain. My own research at the University of Missouri has demonstrated how easily dietary sugars are transformed into fat in the body.

The guidelines also recommend reducing salt as much as possible. Yet numerous recent studies have challenged this advice.

The government isn’t purposefully doling out questionable recommendations. Indeed, its advisory panels are comprised of some of the nation’s leading scientists, and the experts pore over thousands of pages of data. But their process for evaluating research is in need of review.

Making matters even messier, federal officials open up the guidelines for comment after the scientists complete their job. This gives industry stakeholders — primarily agricultural and food lobbyists — an opportunity to have their say, presenting yet another set of hurdles for good science to prevail.

To fix the guidelines, officials should appoint experts with a balance of opinions, especially on key contentious topics such as saturated fats and salt. They should also recognize that different people may need different diets. Science doesn’t support a one-size-fits-all approach to nutrition. Perhaps the government shouldn’t promote one either.

The Academies’ report noted that it’s critical to “enhance transparency, manage biases and conflicts of interest to promote independent decision making, promote diversity of expertise and experience, support a deliberative process, and adopt state-of-the-art processes and methods to maximize scientific rigor.”

That’s completely correct. Embracing sound science and removing politics from the Dietary Guidelines for Americans will require persistence and courage, but getting them right is critical for public health.

Elizabeth Parks is a professor in the University of Missouri’s Department of Nutrition and Exercise Physiology.