MAY / JUNE 2005

AROUND HARVARD

This article originally appeared in the April 2005 Harvard Heart Letter and is provided courtesy of Harvard Health Publications.

New diet guidelines: A few steps forward, a few back

For your heart and overall health, don’t follow all of the government’s healthy eating recommendations.

Every five years, the federal government tells us what we should eat to stay healthy. It’s a daunting task, really, given how many of us there are (nearly 300 million), how different we are, and the ways the Dietary Guidelines for Americans are used. They not only inform the choices that we make as individuals but also direct school lunch programs, food services on military bases, and a host of other federal food programs.

U.S. Health and Human Services Secretary Tommy Thompson called the new guidelines, released in January, “a combination of good science and common sense.” He neglected to mention one other key element — intense pressure from the food industry.

In a nutshell
Here are key points from the Dietary Guidelines for Americans 2005:

Eat for nutrients, not calories. Many of us get more calories than we need, yet are still “down a quart” when it comes to vitamins, minerals, fiber, and other important nutrients. That’s because we tend to avoid foods rich in nutrients, such as vegetables, beans, and whole grains, and opt for those rich in calories but poor in nutrients.

Watch your weight. How much we eat is at least as important as what we eat. Shaving daily intake by just 50–100 calories a day (that’s three bites of a hamburger or three Hershey’s Kisses) may be enough to prevent weight gain.

Exercise. Thirty minutes a day is good for the heart; the waist needs more.

Fat. Limit intake of saturated fats, and avoid trans fats (found in anything containing partially hydrogenated vegetable oils) whenever possible. Embrace unsaturated fats, like those found in fish, nuts, and vegetable oils.

Carbohydrates. Ignore the “carbs are bad” hype! Whole grains, fruits, and vegetables deliver good carbohydrates and healthful nutrients. Go easy on added sugars and highly refined grains, which offer little more than calories.

Fruits and vegetables. Forget five a day. The standard is now nine servings a day, the equivalent of 41⁄2 cups. It’s not as bad as you think — a medium apple or orange is two servings, while one carrot or five broccoli florets is one serving. Aim for a variety of colors (especially orange and dark green vegetables) and varieties.

Dairy. Have three cups a day of low-fat or fat-free milk or yogurt, or three servings of other dairy products.

Some good advice ...
Several of the new recommendations represent important steps forward for the guidelines and (if we follow them) the nation’s health, cardiovascular and otherwise:

Weight control and exercise get top billing, as they should. Neither got much ink in previous versions.

Fats are no longer all tarred with the same brush. In a break from the past, the new guidelines clearly discriminate between good and bad fats. They also jettison the artificially low cap on fat intake. We’re now “allowed” to get up to 35% of daily calories from fats, as long as most of them are heart-healthy monounsaturated and polyunsaturated fats.

The emphasis on “complex carbohydrates,” a term used in the past that has little biological meaning, has been scrapped. We are now urged to choose whole grains whenever possible and to limit added sugars, such as those in sodas, sugared cereals, and the like.

... some bad
The revision isn’t entirely positive. A few of the recommendations remain mired in the past:

The guidelines say it is okay to get half of our grains as refined starch — white bread, white rice, chips, etc. The body responds to these the same way it does to sugar. Refined grains add empty calories, can cause metabolic problems, and increase the risks of diabetes and heart disease.

No guidance is offered on protein other than to “make choices that are lean, low-fat, or fat-free.” This overlooks the evidence that poultry, fish, and beans have different types of fats than red meat, and that eating them instead of red meat offers numerous health benefits. For example, in a long-term study of almost 30,000 middle-aged Iowa women, eating vegetable protein (mostly beans and nuts) in place of one-third of carbohydrates or animal protein cut the rate of heart disease in half. The study, published in the February 2005 issue of the American Journal of Epidemiology, is just the latest in a string of similar evidence.

The most radical change is the recommendation to drink three glasses of low-fat milk or eat three servings of other dairy products per day. The aim is a good one — preventing osteoporosis. But there is scant evidence of a link between consuming more dairy products and preventing osteoporosis. The other drawback is that three glasses of low-fat milk add nearly 400 calories a day. Exercise and supplements of calcium and vitamin D are better ways to strengthen bones.

As the dust settles and the country begins digesting the new guidelines, it’s clear that the dairy and beef industries scored big wins. The mere mention that we should “avoid added sugars” was a blow to the sugar industry. What about the public’s health? On a scale of 1 to 10, it gets about a 6. This is progress, indeed. But we have a way to go before the government’s recommendations fully match what nutrition science today tells us about healthy eating.

Copyright 2006 Harvard Medical International