Focus on variety can lead to eating more unhealthy foods. Here's why

Although doctors and nutrition experts have recommended “eating a variety of foods” for decades, there’s a lack of agreement on what exactly that means and whether it really is a healthy option, according to a new American Heart Association Science Advisory.

Recent studies suggest that diet diversity is associated with poor eating habits that include processed foods, refined grains and sugary drinks and not eating minimally-processed foods such as fish, fruits and vegetables. Diet diversity could lead to weight gain and obesity, the AHA Behavioural Change for Improving Health Factors Committee writes in the journal Circulation.

“While selecting a wide range of healthy foods remains important for good nutrition, expanding food choices to include less-healthy foods such as donuts, chips, fries and cheeseburgers, even in moderation, may translate into eating too much of too many unhealthy things far too often,” said lead advisory author Marcia de Oliveira Otto of the University of Texas Health Science Center at Houston.

The group emphasised the American Heart Association Dietary Recommendations and the Dietary Approaches to Stop Hypertension (DASH) diet as two examples of healthy eating patterns. “The focus should shift to emphasising eating adequate amounts of healthy foods such as fruit and vegetables, protein, low-fat dairy products, vegetables oils and nuts, while limiting intake of less-healthy foods such as sweets, beverages with added sugar and red meats,” de Oliveira Otto told Reuters Health by email.

The committee looked at studies around diet variety, eating patterns and obesity since 2000 to provide an updated perspective for doctors and nutritionists. First introduced in the early 20th century, the concept of promoting “variety” was based on the premise that eating different foods would help people avoid nutrient and mineral deficiencies. During the past two decades, however, more junk food is on the market that ever before, and more diversity doesn’t mean quality.

The committee found there’s no evidence that greater overall dietary diversity leads to healthy eating habits or a healthy weight. In fact, they found some evidence that a wider variety of food options in one meal may delay people’s feeling of fullness and may increase the amount of food they eat.
 

Consumers could use this information to reduce unhealthy behaviours. For example, keeping one flavour of cookies in the house instead of three may reduce the number of cookies being overconsumed, said Megan McCrory of Boston University. McCrory, who wasn’t involved with this advisory, has researched dietary variety and energy balance.

“Another example is buffets and potlucks - everyone who has been to a buffet or potluck is familiar with the idea that it’s difficult to limit the number of items put on their plate because they all look so good, and it’s tempting to taste them all,” she told Reuters Health by email.

Future studies should look at whether diet diversity in certain food groups, such as fruits and vegetables, is related to healthier diet habits or weight control, said Maya Vadiveloo of the University of Rhode Island in Kingston.