What you need to know about the new dietary guidelines

When the federal government released the latest revisions to the Dietary Guidelines for Americans in January, some of the recommendations seemed to turn long-established nutrition advice on its head (literally, as the guidelines featured a new food pyramid, turned upside down).

While experts in the nutrition and public health communities were pleased to see some changes - a new emphasis on avoiding highly processed foods and added sugars, for example, and an overall pitch to "eat real food" - many were also alarmed. Some of the guidelines seemed to overlook years of established science, as well as key recommendations by the Dietary Guidelines Advisory Committee (DGAC), a group of independent nutrition experts.

So, what should you take from the new guidelines? Here's some perspective from two experts who served on the DGAC: Deirdre Tobias, assistant professor of nutrition, and Teresa Fung, adjunct professor of nutrition, both at Harvard's T.H. Chan School of Public Health.

Q: What are the biggest changes from previous guidelines?

A: Key changes fall within the daily protein recommendations, where animal sources like meat, poultry, seafood, eggs, and cheese now get top billing. The pyramid also promotes full-fat dairy products (three servings daily) and adds animal fats like butter and beef tallow to the "healthy fats" category.

The guidelines keep the longstanding recommendation to limit saturated fat to 10% of calories or less - but the abundance of animal products in the pyramid contradicts that, notes Tobias. "It puts people at risk of exceeding the limit," she explains, "and saturated fat as a risk factor for heart disease is very well established."

Many of the guidelines aren't that different from previous recommendations or what the DGAC advised, Tobias says. For example, fruits and vegetables are prominent in the pyramid, and the guidelines advise choosing whole grains. "They retained daily limits for sodium as well as saturated fat, and they continue to emphasize whole foods - which has been a foundational framing of what constitutes a healthy diet for several rounds of the guidelines."

Q: Should we greatly increase our protein intake?

A: The new guidelines urge "prioritizing protein at every meal" with a goal of consuming 1.2 to 1.6 grams of protein per kilogram of body weight daily - up to twice the minimum amount spelled out in the Recommended Dietary Allowance. Though a protein boost might be helpful for some people like seniors, athletes, and people taking weight-loss medications, "most Americans are already getting adequate protein," says Fung. (Plus, diets rich in red meat have long been linked with higher risks of heart disease, colon cancer, and diabetes.) Focus instead on switching some of your proteins from dinner to breakfast, when you need to take in fuel for the day; many Americans eat their biggest protein meal at night.

Prioritize getting a variety of protein sources, Fung adds, as you can meet all your protein needs with plant foods - especially beans and legumes. "There's really no need to increase your animal protein intake," she says. Choosing plant-based protein sources also ensures you'll get the fiber, folate, and phytonutrients plant foods supply, which are often lacking in Americans' diets.

Q: Do we really need three glasses of full-fat milk daily?

A: It's a matter of preference, says Fung. "There's a fair number of people who have some lactose intolerance, and others just don't like dairy." Moreover, she adds, "every nutrient in dairy foods can be obtained elsewhere in the food supply." For example, greens, beans, and tofu are good calcium sources, as are fortified plant-based milks and orange juices (which also often contain added vitamin D).

Another consideration: drinking that much whole milk adds a significant amount of saturated fat to your diet (about 5 grams per 8-ounce glass, which approaches the daily limit of 22 grams daily for a 2,000-calorie diet).

Q: Are beef tallow and butter truly "healthy fats"?

A: Touting these highly saturated fats as "healthy" poses another contradiction, says Tobias. Extensive research shows that "decreasing saturated fat and replacing those calories with poly- and monounsaturated fats is consistently related to lower cardiovascular disease." (Vegetable oils are good sources of those healthy fats.)

Q. What does "limit alcoholic beverages" actually mean?

A: The new guidance replaces formerly specific limits with advice to "consume less," which is "not very actionable," admits Tobias. It might make sense to stick to the previous limit of no more than two daily drinks for men, one for women. "It's very clear from the evidence that drinking more than that is linked with higher risk of heart disease, cancer, or death from any cause."

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