Americans need to make a healthy body weight a top priority as they decide what to eat and should make time for 30 to 90 minutes of daily physical activity, the government said yesterday in the first revision of its recommended dietary guidelines in five years.
The U.S. Dietary Guidelines, jointly issued by the departments of Health and Human Services and Agriculture, provide a recipe for healthful eating for the nation. By law, they must be applied to menu planning for school lunches, to supplemental nutrition programs for the poor and to set health policy objectives for the nation.
The guidelines are updated every five years by congressional mandate. The latest set offers 41 recommendations that direct Americans to eat more fruit, vegetables, whole grains, beans and low-fat or nonfat dairy products. That advice is far afield from the Atkins and other very low-carbohydrate diet programs that many Americans have flocked to in recent years.
In urging consumers to eat less highly processed foods with unhealthful fat, added sugar and too much salt, the 71-page Dietary Guidelines -- one of the largest and most detailed ever issued -- also put to rest speculation by consumer groups that food industry interests might dilute the recommendations.
"They look to me like the strongest Dietary Guidelines yet produced," said Michael Jacobsen, director of the Center for Science in the Public Interest, an advocacy group that has often been critical of past guidelines. "The major emphasis is on fruit and vegetables, whole grains and low-fat dairy products. . . . It's consistent with the advice to move Americans towards a more plant-based direction."
In August, a 13-member scientific advisory committee issued a voluminous report calling for Americans to cut back on foods with high levels of sodium, unhealthful saturated and trans-fatty acids, cholesterol and added sugars, such as soft drinks. That committee based those recommendations on an extensive review of the scientific literature that awarded a grade for the quality of each study it considered.
"What that means is that every conclusive statement in the report had to be supported with adequate scientific evidence," said Russell Pate, a professor at the University of South Carolina's Arnold School of Public Health in Columbia and a member of the advisory committee. "We put an incredible amount of time in compiling and creating the evidence-based tables."
The advisory committee's report is not binding, however, and some members disagreed strongly on the question of what role sugary food and drink play in fueling the obesity epidemic. The debate was so contentious and long that committee Chairman Janet C. King, a senior scientist at the University of California at Berkeley and Davis, convened an additional meeting to help iron out the differences.
Carlos Camargo, one of the committee members who argued strongly for limits on food with added sugars, praised the new dietary guidelines. He noted that a companion consumer report, also issued yesterday, strengthened the recommendations to avoid sugar-sweetened food and drink.
Specifically, the report advises Americans: "When grabbing lunch, have a sandwich or whole-grain bread and choose low-fat/fat-free milk, water or other drinks without added sugars."
"I've never seen a document from the federal government that says to choose drinks without added sugars," said Camargo, an assistant professor of medicine at Harvard Medical School, in a Center for Science in the Public Interest news briefing. "I'm going to be talking a lot about that."
Some food industry groups, however, expressed disappointment. "We stand firm in our assertion that every major scientific review, including the Institute of Medicine macronutrient report, has concluded that there is not a direct link between added sugars intake and any lifestyle disease, including obesity," said Andy Briscoe, president and CEO of the Sugar Association. "For the guidelines to infer any type of limit on added sugars is not science-based."
The Sugar Association also noted that if people consume more calories than they burn, "weight gain is inevitable."
Although exercise earned a mention in previous guidelines, the latest recommendations strongly urge Americans to engage "in regular physical activity and reduce sedentary activities to promote health, psychological well-being and a healthy body weight."
The guidelines say that to reduce the risk of chronic disease, adults need to engage in "at least 30 minutes of moderate-intensity physical activity," above what they do at work or home, on most days of the week.
To lose weight or avoid the added pounds that creep on every year for most adults takes even more work -- about 60 minutes of moderate to vigorous intensity activity on most days of the week, the guidelines conclude. Those trying to sustain weight loss will probably need at least 60 to 90 minutes of moderate activity daily, the document adds.
Some experts worried that the guidelines set the bar too high for a largely sedentary U.S. population.
"It's a legitimate concern," Pate, of the advisory committee, said. "Frankly, I cringe a little at the 90-minute recommendation for maintenance of lost weight. But we were charged with approaching the guidelines from an evidence-based perspective, and we did our level best to do that. I certainly believe that the 30-minute guideline is the best for overall chronic disease risk reduction and health maintenance."
The new guidelines "offer important advice on healthy eating, but unless accompanied by more aggressive and comprehensive efforts to combat obesity, they are not likely to have much of an effect," said Sen. Tom Harkin (D-Iowa), who has long urged more healthful food in schools. "These guidelines should only be considered a starting point. Much more needs to be done in Congress and throughout our communities to give Americans the tools they need to eat right and maintain a healthy weight."