The first thing Dr. Walter Willett, Chair of the Harvard Nutrition Department, eats in the morning is a bowl of oatmeal with walnuts and blueberries. Dr. Barry Popkin, Professor of Nutrition at UNC Chapel Hill and one of the most cited researchers in the world, eats a bowl of Nature’s Path cereal with organic blueberries he froze last summer. Dr. Dariush Mozaffarian, Dean of Tuft’s School of Nutrition Science and Policy eats a bowl of Kashi cereal with walnuts, blueberries and raspberries, while Dr. David Levitsky, Professor of Nutrition at Cornell, drinks the juice of two oranges. Willett, Popkin, Mozaffarian and Levitsky are not the authors of fad diet books. They are the top nutrition researchers in the world.
I asked these four leading nutritional scientists to recall all the foods and beverages they consumed over the last 24 hours. Given their wide range of research interests and backgrounds, I was surprised by the similarities—down to the berries on their breakfast cereal.
Three of the four had a glass of wine with dinner, but none could remember the last time they had a soda, Gatorade or other sugar-sweetened beverage. “Maybe back in college?” Mozaffarian guessed. Clearly, they’ve been adhering to some of these dietary behaviors for a while.
All four try to have fish at least once per week. All eat red meat infrequently, having it once per week, every other week, or even once a month. All had vegetables with both lunch and dinner. As you might expect in a group of academics from the country’s top universities, coffee was common. Two of the four even had ice cream, although they don’t every night.
Of course, there were some points of contrast in their diets. Levitsky considers himself an all-around “caloric restrictor.” Willett actively limits salt. Popkin and Mozaffarian limit their carbohydrate intake, except for fruit and beans, while Willett usually has whole grains for breakfast, lunch and dinner. Levitsky cooks with store-brand vegetable oil; Mozaffarian, Willett and Popkin emphasize the use of extra virgin olive oil.
The results of my informal survey illustrate a larger point. Overall, these nutrition experts tend to eat a diet with fruits, vegetables, whole grains, vegetable oils, nuts and fish, while limiting red meat, refined carbohydrates and added sugars. They’ve integrated years of scientific knowledge into their daily food and beverage choices, and they take pleasure in their diets. They eat this way because it tastes and feels better.
As the 571-page Dietary Guidelines Scientific Report suggests, nutrition is complex. The conceptual model takes an 8-page table to explain. The first chapter (which does not begin until page 74) has 114 references. The more we learn about nutrition and disease, the more we realize just how complex their association is. But that does not mean we cannot apply current knowledge to our day-to-day lives.
If Americans continue to eat unhealthy diets linked with chronic diseases like diabetes and heart disease, it’s not because of the Dietary Guidelines. It’s because of the food and restaurant industry, oversized portions, and readily available high-calorie foods. It’s because of aggressive marketing of unhealthy foods. These should be the targets of criticism. Not the Dietary Guidelines. And not nutritional science.