Consumption of certain fruits and vegetables are encouraged under national guidelines for reducing risks of chronic diseases. These powerhouse fruits and vegetables (PFV) are not clearly defined, however. A new project was conducted to address this gap in nutritional definitions, and the results are published in this week’s issue of Preventing Chronic Disease, a peer-reviewed publication of the National Center for Chronic Disease Prevention and Health Promotion within the U.S. Centers for Disease Control and Prevention.

Although PFVs are described as being leafy green, yellow or orange, citrus, or cruciferous, a clear and complete definition what constitutes a PFV has been lacking. Dr. Jennifer Di Noia of William Patterson University endeavored to change this by establishing clear and sensible criteria for defining PFVs. Di Noia decided to define PFV as “foods providing, on average, 10 percent or more daily value per 100 kilocalories (one kilocalorie is equal to one “food” calorie used in casual terms) of 17 qualifying nutrients.”

“I decided to look at densities of key nutrients in foods belonging to the aforementioned groups,” said Di Noia in an interview with the Huffington Post. “I thought it would be easier for consumers to have a PFV list as there is often confusion about which foods belong in which groups.”

Out of 47 foods that Di Noia considered based on a review of the scientific literature, 41 satisfied the criteria for being designated as PFVs. These PFVs passed through a three-step process. First, a list of 17 nutrients identified as important in public health by the Food and Agriculture Organization of the United Nations and the Institute of Medicine was used for candidate food screening. This was accomplished with foods in their raw forms.

Nutrient density scores were then assigned to the candidate foods by existing methods, and the classification of the foods as PFVs was validated by correlation statistic estimates.

“The PFV list will help consumers know what PFV are and help them choose them as part of their overall fruit and vegetable intake,” said Di Noia. “The scores may help focus consumers on their daily energy needs/how best to get the most nutrients from their foods.”