Defining hyper-palatability: Study finds over half of US foods encourage overeating

08 Nov 2019 --- Gone are the days of clumsily reaching for a catch-all term for often-processed foods with alluring combinations of fat, sugar, carbohydrates and sodium – a new study has created a data-driven definition of “hyper-palatable” foods (HPF). Published in Obesity, the paper discovers that most foods consumed in the US meet these hyper-palatable definitions. The researchers now hope that the findings will be used to guide policymakers to educate consumers and improve children’s diets.

“The US Food and Drug Administration (FDA) could require labeling of foods as hyper-palatable to alert consumers about what they may be eating while preserving consumer choices. It would also be possible to have the FDA regulate specific combinations of ingredients to decrease the chances that people find these foods difficult to stop eating, even when they are full. For example, they could limit the sodium content of foods to less than 0.3 percent per gram per serving if the food also contains more than 25 percent calories from fat,” lead author Tera Fazzino, Assistant Professor of Psychology at the University of Kansas and Associate Director of the Cofrin Logan Center for Addiction Research and Treatment, tells NutritionInsight.

The researchers extracted common HPF descriptive definitions from previous literature and used nutrition software to quantify ingredients of fat, simple sugars, carbohydrates and sodium. These mixes of ingredients are apt to light up people’s brain-reward neural circuitry and overpower mechanisms that are supposed to signal when enough has been eaten. The team found that HPF foods tended to have one of three nutritional profiles, with varying levels of frequency:

• Derives more than 25 percent calories from fat and is at least 0.30 percent sodium by weight (70 percent of HPF). Examples include meat dishes or egg and milk-based foods like omelets or cheese dips.
• Derives more than 20 percent calories from fat and more than 20 percent from sugar (25 percent of HPF). Examples include cake, ice cream and brownies.
• Derives more than 40 percent calories from carbohydrates and at least 0.20 percent sodium by weight (16 percent of HPF). Examples include crackers, pretzels and popcorn.

These definitions were then applied to 7,757 food items in the US Department of Agriculture’s Food and Nutrient Database for Dietary Studies (FNDDS). It was found that 62 percent of these foods met HPF criteria, which included some vegetables cooked in creams, sauces, or fats, as well as foods with reduced- or low-fat claims. 

The previously used descriptive definitions of palatable foods lack specificity regarding the ingredients.Fazzino was surprised to find that among foods in the US database that were labeled as having no, reduced, or low levels of sugar, fat, sodium, or calories, 49 percent were hyper-palatable. These findings indicate that many foods marketed for weight management may have characteristics of enhanced palatability.

“Additionally, while most research has focused on ingredients such as sugar and fat, we found that sodium was an important ingredient and was present in two of the three clusters of foods that make up the hyper-palatable food definition,” she notes. 

The previously used descriptive definitions of palatable foods lack specificity regarding the ingredients that may be implicated in hyper-palatability, Fazzino explains. “Without a standardized definition that is quantitatively based, it is difficult to inform prevention efforts, such as public policy regulation. For example, while we can’t regulate categories of foods, such as desserts, we could provide specific information to legislators regarding the specific levels of ingredients that may enhance palatability in a way that may make foods difficult to stop eating.”

The next step for this area of research is to determine whether this definition is associated with a variety of constructs related to overeating, obesity, and obesity-related chronic diseases such as Type 2 diabetes. “Doing so will provide us with evidence supporting the validity of the definition. I also plan to examine the differences in the prevalence of hyper-palatable foods between the US and other countries, such as Italy,” concludes Fazzino.

Other research is also exploring the psychology of junk food cravings. Earlier this year, a study found that in cases of obesity resulting from consuming a high-fat diet or overeating, the body stops responding to natural hormonal signals of satiety, or “fullness.” Previous research also found that obese people have higher initial taste perceptions of chocolate that decline at a more gradual rate than non-obese people. 

By Katherine Durrell