When it comes to dietary recommendations, "eat a variety of foods," probably echoes in the back of our minds with how often we hear it. But a new scientific statement suggests that it may not be the best piece of advice after all.

The paper titled "Dietary Diversity: Implications for Obesity Prevention in Adult Populations" was published in the American Heart Association (AHA) journal Circulation on August 9.

The statement authors conducted a thorough scientific literature review of articles published over the course of nearly two decades i.e. between January 2000 and December 2017.

The recommendation to eat a variety of foods has been around since the early 20th century to help tackle nutrient inadequacies, they wrote. But when examining newer evidence, associations with lower diet quality and excess food intake have been found. 

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

The findings of the review indicated no evidence that overall dietary diversity could promote healthy weight or optimal eating. Secondly, the amount of food consumed may be increased as some evidence found that a variety of food options in a meal could delay the feeling of fullness

And finally, limited evidence suggested an association between greater dietary diversity and higher calorie intake, poor eating patterns, and weight gain in adults.

The review also highlighted a need for a standardized measure to help define what diet diversity is and whether certain aspects of diet diversity could help boost potential health benefits.

"Currently, there is a lack of consensus about what dietary diversity is and how it is best measured," the authors stated in the paper. "Understanding the different concepts and measures of dietary diversity is critical to improving our understanding of what a diverse diet is and how it may influence current dietary patterns that are relevant to obesity."

But rather than to emphasize variety, the authors believed in simply prioritizing nutritious, plant-based foods and limiting red meat, sweets, and sugary beverages. A good diet would contain fruit, vegetables, beans, whole grains, low-fat dairy, non-tropical vegetable oils, nuts, poultry, and fish. 

The authors noted examples of healthy eating patterns such as the AHA dietary recommendations as well as the Dietary Approaches to Stop Hypertension (DASH Diet).

"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 donuts, chips, fries, and cheeseburgers, even in moderation," Otto added.