"Eating a more diverse diet might be associated with eating a greater variety of both healthy and unhealthy foods. Combined, such an eating pattern may lead to increased food consumption and obesity," statement author Marcia de Oliveira Otto said in an AHA news release.

Otto is an assistant professor of epidemiology, human genetics and environmental sciences at the University of Texas School of Public Health in Houston.

The statement challenges advice to eat a variety of foods that's been included in public health recommendations in the United States and many other countries for decades.

But there's little agreement about what that means and whether it's a healthy approach.

The statement authors reviewed studies published between January 2000 and December 2017 and concluded there is no evidence that eating a greater variety of foods is healthier or promotes a healthy weight.

In fact, some evidence suggests a greater number of food choices in a meal may delay people's feeling of fullness, leading them to eat more. Limited evidence suggests that a more diverse diet is associated with higher calorie intake, poor eating patterns and weight gain in adults.

The statement was published Aug. 9 in the AHA journal Circulation.

It concludes that dietary recommendations should encourage people to eat adequate amounts of fruits, vegetables, beans and whole grains, low-fat dairy products, non-tropical vegetable oils, nuts, poultry and fish, and to limit red meat, sweets and sugary drinks.

"Selecting a range of healthy foods, which fits one's budget or taste, and sticking with them, is potentially better at helping people maintain a healthy weight than choosing a greater range of foods that may include less healthy items such as doughnuts, chips, fries and cheeseburgers, even in moderation," Otto said.