The new AHA recommendations, published October 1, 1997 in the journal Circulation, are more consistent with the guidelines of the U.S. Department of Agriculture and the Department of Health and Human Services. The last update by the AHA was in 1988.

Ronald Krauss, M.D., chairman of the AHA's volunteer Nutrition Committee, says, "Perhaps the most dramatic change is that we are emphasizing the characteristics of the total diet (over several days or a week) rather than what one eats in any given meal or even on a given day. This allows some flexibility in choosing foods and fits the theme of consuming a variety of foods and reducing guilt from eating something 'bad' now and then."

Some of the other significant changes in the guidelines are:

• A stronger emphasis on weight maintenance and physical activity in view of the alarming tendency toward increasing obesity in the United States;
• Acknowledgement that genes influence an individual's response to fat, cholesterol, and salt, and that an eating plan may need to be tailored to fit a person's metabolism or risk profile;
• Endorsement of the World Health Organization recommendation that people need a certain amount of fat in their diets: at least 15-percent of calories should be from fat;
• A recommended intake of monounsaturated fats: 10 to 15-percent of calories should be in the form of monounsaturated fats, versus a previous recommendation of less than 10-percent of calories as saturated fat, less than 10-percent of calories as polyunsaturated fat, and the balance as monounsaturated fat (with the maximum amount of calories from fat set at 30-percent of total caloric intake);
• A new recommendation of 25-30 grams of fiber per day from foods, not from supplements (25-30 grams is about 0.9-1.1 ounces);
• A new recommendation to "choose a diet moderate in sugar," that is, to avoid foods high in sugar; and
• A change in the recommended salt intake: no more than 6 grams per day (a little more than one teaspoon), down about 35-percent from earlier guidelines. Most salt consumed is from high-salt cured and processed foods rather than from a salt shaker. All salt consumed, in whatever form, should be factored into the total daily salt consumption.

Dr. Krauss notes, "There are many refinements but no fundamental changes from our tried-and-true guidelines. Over the years, they have been very effective in helping to decrease heart disease risk in the United States."

The AHA identifies some dietary issues requiring more research, notably antioxidant vitamin supplements, vitamin intake as it relates to homocysteine levels (an independent predictor of heart disease risk), very low-fat diets and fat substitutes, diet supplementation with omega-3 fatty acid (found in fish oils), soy protein, and genetic factors affecting dietary response to foods and nutrients. The Nutrition Committee plans to publish scientific statements in each of these areas and update them regularly to reflect changing research.