Others have proposed reshaping the pyramid into a bowl or a following Canada’s model and using a plate. According to Blackburn, the problem lies not with the guide itself but with a widespread indifference toward good eating habits.

“If people did the existing pyramid we wouldn’t need a new one,” he said.

The Fruits of His Labor

Blackburn’s passion for nutrition began early in his career.

As a doctor in the intensive care unit, he noticed that obesity was destroying patients’ health,

“I saw all these overweight people and I saw they weren’t getting there overnight,” he recalls.

This realization motivated Blackburn to return to school, where he earned a doctorate in nutritional biochemistry from Massachusetts Institute of Technology in 1973.

Since then he has been obsessed with nutrition. And his office bears the fruits—and vegetables—of his labor.

On his desk, among the papers of nutritional arcana are drawings of incarnations of the food pyramid. An unopened weight-loss shake sits on the side of the desk—for demonstration, not use. Plastic tomatoes, carrots and apples rest on the shelf behind him, next to a plastic bread loaf and an incongruous miniature lobster.

Though his office shows the lighter side of healthy eating, for Blackburn, nutrition is no laughing matter.

He estimates that the U.S. could save $100 billion in health care expenses if Americans followed healthier regimens.

Though the food pyramid debate weighs heavily on the minds of some nutritionists, Blackburn says the issue of super-sizing will “trump” any changes to the pyramid.

Increased portions are fueling the obesity epidemic, he says.

“We have to use some characterization of serving size that people recognize,” he says, pinching the base of his thumb.

“A serving of cheese is the size of your thumb. The pyramid is not helping people understand,” he says. “They are eating too many servings that are too big.”

—Staff writer Jonathan P. Abel can be reached abel@fas.harvard.edu.