A new book released this week and authored by a Harvard nutrition expert challenges the validity of the U.S. Department of Agriculture’s standard food pyramid.

Professor Walter C. Willett, the chair of the nutrition department at the Harvard School of Public Health (SPH), offered his alternative pyramid in his new book, “Eat, Drink, and Be Healthy.”

Willett’s “Healthy Eating Pyramid” differs greatly from the USDA’s well-known version, which has been taught to students in schools and displayed on bread, cereal and pasta packaging in the years since its inception in 1992.

The new pyramid restructures the USDA version from the ground up.

Weight control—and not 6-11 servings of complex carbohydrates—should serve as the base of a pyramid which promotes long-term health, Willett said.

“When it comes to long-term health, keeping your weight from creeping up on you is more important than the exact ratio of fats to carbohydrates or the types and amounts of antioxidants in your food,” Willett wrote.

Willett’s pyramid emphasizes the significance of weight control and puts a greater stress on two less recognized dietary concerns—good fats and bad carbohydrates. It also suggests regularly consuming vegetables and fruits, using alcohol in moderation, and taking a daily multivitamin.

As part of the research backing up the new pyramid, Willett debunks two common food myths: first, that all fats are bad and second, that all complex carbohydrates are good.