Healthy Diets Need Fat, According To New Study

"Fat is back,'' said Adam Drewnowski, director of the Human Nutrition Program at the U-M School of Public Health. While most nutrition experts continue to recommend low-fat diets that are high in vegetables and fruit, dieters are making the most of meat, chocolate and ice cream. The latest diets for weight loss have skipped starches in favor of more protein and fat, but all is not lost.

"Diversity and variety contribute as much to diet quality as does low fat content,'' Drewnowski said. "A monotonous diet of two or three low-fat foods may do wonders for your cholesterol levels, but will do nothing for your mental health or your quality of life. The premier U.S.D.A. recommendation is to enjoy a variety of foods. That is the one guideline that we should follow.

"As nutrition experts, we should recognize that some fat in the diet is not necessarily a bad thing."

Drewnowski will present his research findings on Tuesday (April 21) at the Experimental Biology Meeting in San Francisco.

He and a team of U-M researchers, including Dr. E.C. Chung, a visiting scholar from Korea, recently explored new ways to measure diet quality. They examined the overall diet of men and women in the United States based on diet diversity (consuming foods from the five major food groups), variety (total number of foods consumed per day) and moderation (following U.S.D.A. food guidelines). The team examined the eating habits of 1,637 men and 1,576 women over two days. The statistics were taken from the 1995 Continuing Survey of Food Intakes of Individuals by the U.S.D.A. They compared those results with a 1995-96 study in Paris that examined the eating dietary habits of the 5,000 French adults.

French men and women ate more foods higher in fat, saturated fat and cholesterol than Americans did. The typical French diet met few of the U.S.D.A. recommendations for healthy eating. The study concluded that 99 percent of the French women derived more than 10 percent of their calories from saturated fat and yet the French have fewer cases of heart disease and are less obese than Americans.

The consumption of fat in the French diet was balanced by greater dietary diversity and variety. "The low-fat approach is very good, but not if it comes at the expense of dietary variety," Drewnowski said.

The U.S.D.A. recommends that Americans eat a variety of foods. Drewnowski found that those people who had more diversity in their diets, consumed more calories, fat, saturated fat, cholesterol and fiber. Typically, men had more diverse diets than women did. Elderly women consumed the least fat and had much less diverse diets. Only one in 10 men and one in 16 women consumed at least one serving of each of the five good groups: meat, dairy, grains, vegetables and fruits over two days.

The U-M researchers also discovered that eating a variety of foods is associated with extra costs. The study showed that those who subscribed to more varied diets tended to be older and richer. "The fact that greater dietary variety is associated with higher incomes is troubling. The challenge then to public health nutritionists is how to issue dietary guidelines in a way that a healthy diet is accessible to all regardless of income," Drewnowski said.

The U.S.D.A. is currently forming an advisory committee that will begin its review of food guidelines this fall.