Y
ou might think the government's new food pyramid and website would address the nation's obesity epidemic. But according to nutrition experts at the Harvard School of Public Health (HSPH), both are light--make that lite--on guidance concerning what to eat, how much to eat, and what foods to avoid.

The pyramid, an overhaul of the iconic 1992 version, is at best a sketchy roadmap to healthful eating, the HSPH experts say. Unveiled by the U.S. Department of Agriculture in April, the graphic sports six vertical stripes, color-coded for the basic food groups: grains, vegetables, fruits, oils, milk, and meat and beans. The stripes vary in width, hinting vaguely at what their relative proportions in one's daily diet should be. To one side of the pyramid, a stick figure climbs, reminding us to exercise--the graphic's best feature, many say.

Information can be gleaned mainly through the Internet. At http://www.mypyramid.gov, visitors can input their age, gender, and activity levels. In return, they learn how many cups and ounces of each food category to eat each day.

No mention is made of weight and height--"probably the most important measurements" needed for calorie planning purposes, says Walter Willett, chairman of HSPH's Department of Nutrition.

HSPH Associate Professor of Epidemiology Carlos Camargo has another concern. A member of the advisory committee that wrote the dietary guidelines on which the pyramid is based, Camargo says two words are missing from the government's message: Eat less.

Unfortunately, Camargo says, the U.S. Department of Agriculture (USDA) appears to have built its pyramid system on the politically safe principle that "all foods are good foods." The system fails to differentiate between good fats (such as fish oil) and bad fats (such as trans fats, abundant in bakery items and fried foods). Likewise, he says, it does a poor job of helping users sift good carbohydrates (whole wheat pasta) from bad (refined sugars found in soft drinks).

The upshot is a half-baked message. A 40-year-old woman, for example, is advised to eat 6 ounces of grains, 2.5 cups of vegetables, 1.5 cups of fruit, 3 cups of milk, and 5 ounces of meat and beans a day. She learns little of the dangers of added sugars, sodium, trans fats, or excessive alcohol use. And her current weight is never factored into the website's recommendations; she is merely advised to monitor her weight and "adjust calorie intake as necessary."

Look to the Guidelines
Ironically, though the pyramid system may be deeply flawed, the dietary guidelines on which MyPyramid.gov is based are "the best that have come out in years," Camargo says.

Since 1980, the U.S. Department of Health and Human Services has been required by law to update the U.S. Dietary Guidelines every five years to reflect the latest research and nutrition professionals' recommendations. The guidelines help the government select food for the U.S. military and National School Lunch, Food Stamp, and Women, Infant, and Children (WIC) programs.

Though the 2005 guidelines water down some of the committee's recommendations, Camargo says, they "do provide some of the details that are needed to make tough choices." For example, while they stop short of saying trans fats should be eliminated, they give detailed information on fats good and bad. For the first time, they encourage Americans to limit their sugar intake. Moreover, they urge people to control their weight and eat less. Interested readers can peruse all 80 pages at http://www.health.gov/dietaryguidelines/.

HSPH's Pyramid
The best thing about the new pyramid, says HSPH's Willett, is that it's "so complicated, most people will ignore it." In his view, Americans will be better off consulting the alternative pyramid built at HSPH from evidence gathered from the large, long-term Nurses' Health and Health Professionals Follow-Up studies. First introduced in Willett's 2001 book, Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating, HSPH's Healthy Eating Pyramid is posted on the School's website at http://www.hsph.harvard.edu/nutritionsource/pyramids.html; an update of it and Willett's book were published by Simon and Schuster in July.

An at-a-glance guide to eating and staying well, the graphic addresses weaknesses Willett found in the defunct 1992 USDA model, which erroneously asserted that "all fats are bad; all complex carbohydrates are good; all protein sources offer the same nutrition; and dairy should be eaten in high amounts. None of this is accurate," Willett said at the time.

HSPH's pyramid is a monument to healthy eating, many nutrition gurus say. Its base is constructed from the bricks of daily exercise and weight control. Meanwhile, foods considered unhealthy, like saturated fats (red meat, butter) and simple starches (potatoes, white rice), are marginalized at the tip.

Need proof? To see how well HSPH's dietary principles stacked up against the government pyramids, Willett, HSPH Chair of Epidemiology Meir Stampfer, and colleagues correlated both sets of recommendations with real-world choices made by nurses and health professionals from the two studies cited above. Men and women who adhered most closely to the Healthy Eating Pyramid saw the biggest drops in their risk of major chronic diseases. For example, men cut their heart disease risk by almost 40 percent, while women lowered their risk by nearly 30 percent. (For details, visit the HSPH website cited above.)

Paula Hartman Cohen has written for Newsday, the Chicago Tribune, PBS television, and health-related trade magazines.

 

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