For decades nutrition experts have encouraged Americans to eat a variety of foods to ensure that they consume a nutritionally adequate diet. But this week a panel of experts said that longstanding recommendation might be outdated.
The advice to consume a variety of foods has long been included in the federal government’s Dietary Guidelines for Americans. It is largely based on old studies of low-income populations that found that consuming a broad range of foods helped prevent nutritional deficiencies.
But in today’s environment, where food is plentiful and malnourishment less prevalent, that advice could backfire, said Marcia Otto, an assistant professor in the department of epidemiology, human genetics and environmental sciences at UTHealth School of Public Health in Houston.
Dr. Otto was part of a panel of experts with the American Heart Association that examined the latest evidence behind the recommendation. The panel released a scientific report on Thursday in the journal Circulation that found that in some studies, people whose diets contained the greatest variety of foods tended to eat many nutritious foods, like fish, fruits and vegetables, but also many junk foods, such as sugary snacks and beverages, refined grains and other processed foods.
Greater dietary variety was also linked to a higher overall calorie intake and weight gain. Small clinical trials indicate that a wider variety of food options in any given meal could delay fullness and increase the amount of food people eat. The most recent dietary guidelines, published in 2016, recommend that people eat “a variety” of foods, and in particular “a variety of vegetables from all of the subgroups.”
But Dr. Otto said people should worry less about variety and more about diet quality, even if it means filling half your plate with one or two vegetables you like and avoiding others. Ultimately it’s the amount of fruits, vegetables, nuts and other nutritious foods you eat that matters, not the variety, she said.
“We want the general public to know that it’s O.K. if your diet is not very diverse if you’re focusing on healthy foods and trying to minimize consumption of unhealthy foods,” she said.