Study sheds light on unhealthy hyper-palatable foods

By Lois Zoppi, B.A.Nov 5 2019

Research published in Obesity on 5 November 2019 has devised specific parameters that could help to classify certain foods as “hyper-palatable”, a term used to describe food that overpowers the brain’s mechanisms to curb appetite through its combination of ingredients that tap into reward circuitry in the brain.

Image Credit: beats1 / Shutterstock.com

What are Hyper-Palatable Foods?

Before now, there has not been a widely accepted quantitative definition of hyper-palatable food, but the effects of eating these types of foods (often processed food and sweets high in sugar, sodium, fat, and carbohydrates) have been widely studied and documented.

Multiple documentaries have pointed out that food companies have very well-designed formulas for these types of foods to make them palatable and essentially enhance consumption.

But these definitions are virtually unknown to the scientific community, which is a major limitation. If there’s no standardized definition, we can’t compare across studies – we’ve just typically used descriptive definitions like ‘sweets’, ‘desserts’ and ‘fast foods’."

Tera Fazzino, Lead Author and Assistant Professor at the University of Kansas (KU)

Fazzino continued, "That type of descriptive definition isn’t specific to the actual mechanisms by which the ingredients lead to this enhanced palatability. This has been a substantial limitation in the field I thought was important to try to address.”

Creating a Concrete Definition

Fazzino and her University of Kansas research team aimed to set out these definitions in a more concrete manner through a literature review followed by a test applying their definitions to 7,757 food items listed in the US Department of Agriculture’s Food and Nutrient Database for Dietary Studies (FNDDS) using nutrition software.

Fazzino spoke further on the process.

"We essentially took all of the descriptive definitions of the foods from the literature - for example... mac and cheese - and we entered these one by one into a nutrition program that is very careful in how it quantifies a food's ingredients.

"This nutrition software essentially provides in fine-grained detail a data set that specifies how many calories per serving are in this food, and how much fat, sodium, sugar, carbohydrates, fiber and all sorts of other things."

What Makes These Foods Hyper-Palatable?

The researchers searched for food that matched the criteria they devised through their literature review, which included food properties that enhanced palatability, in particular where “the synergy between key ingredients in a food creates an artificially enhanced palatability experience that is greater than any key ingredient would produce alone.”

This means that the individual ingredients of a fast food item, like French fries or burgers, are not that powerful by themselves, and would be unlikely to trigger the reward circuit in the brain that leaves us wanting more food even when we are full. However, in combination, these ingredients work powerfully to increase the desire to eat more and more.

David A. Kessler, author of The End of Overeating: Taking Control of the Insatiable American Appetite and former head of the US Food and Drug Administration (FDA) said that eating hyper-palatable foods that are extremely easy to get hold of can result in “conditioned hypereating”, which has been likened to food addiction.

However, food addiction as a condition has been met with some criticism and as such, whether eating hyper-palatable foods can result in an addiction-like consumption loop is yet to be proven.

From this, they were able to identify foods that matched criteria for three distinct “clusters”, from food containing combinations of fat and sodium, combinations of fat and simple sugars, and combinations of carbohydrates and sodium.

“Essentially, we wanted to identify foods that appear to cluster together with what appeared to be like similar levels of at least two ingredients, because that’s the theoretical basis for inducing the synergistic palatability effect,” Fazzino explained.

“Through a visualization process, we were able to see there were essentially three types of foods that appeared to cluster together in terms of their ingredients.”

How Common are Hyper-Palatable Foods?

By applying their findings concerning the hyper-palatability of foods to the food listed in the FNDDS, Fazzino and her research team hope to be able to find out how common hyper-palatable foods are in the American diet.

They found that 62 percent of the food listed in the FNDDS did meet the criteria for at least one of their three ingredient clusters. Of those foods, 70 percent were high in fat and sodium, like meat dishes, or were meals based on eggs or milk, like omelets or cheese dips.

Furthermore, 25 percent of the hyper-palatable food was high in fat and sugar, and 16 percent of the food was high in carbohydrates and salt. Increasing the precision of their definitions even further, the researchers also discovered that less than 10 percent matched more than one cluster at a time.

Although Fazzino believes more evidence is needed to support their definitions, she believes that “if research begins to support that these foods may be particularly problematic for society, I think that could warrant something like a food label saying 'this is hyper-palatable.”

"We might even think about the restriction of certain types of foods that are available in certain places - for example, in elementary school cafeterias for kids whose brains are still developing and who may be impacted by these types of foods,” she continued.

A particularly concerning discovery is that many foods labeled as reduced or no fat, sugar, salt, or calories made up 5 percent of the foods they defined as hyper-palatable, which may shed doubt on how much healthier these types of foods really are.

With a grant being used to compare American food to food eaten in Southern Italy, where the Mediterranean diet is extremely common (a diet that is gaining traction in its reputation as one of the healthiest types of diets), Fazzino also aims to develop her work further by analyzing how pervasive hyper-palatable food is in the American diet, and comparing the results to other countries.