Ultra-processed foods are viewed as no more appealing than less processed foods, research has found.
A University of Bristol study compared the taste perception of different food types to test the theory that calories and level of processing are key factors influencing how much we like and desire food.
The study’s lead author, Prof Peter Rogers, said the results “challenge the assumption that ultra-processed foods are ‘hyperpalatable’, and it seems odd that this has not been directly tested before”.
Participants in the study, made up of 224 adult volunteers, were presented with colour images of 24 to 32 familiar foods, including avocado, grapes, cashew nuts, king prawns, olives, blueberry muffins, crispbread, pepperoni sausages and ice-cream.
The foods all varied in calories, levels of processing (including UPFs) and carbohydrate-to-fat ratio.
The volunteers were then asked to rate the foods for taste pleasantness (liking), desire to eat, sweetness and saltiness, while imagining tasting them.
Results from the study, published in the journal Appetite, showed that, on average, UPFs were no more liked or desired than processed or unprocessed foods.
They also found foods tasting more intense (mainly related to the level of sweetness and saltiness), were more liked and desired.
“While ultra-processing didn’t reliably predict liking (palatability) in our study, food carbohydrate-to-fat ratio, food fibre content and taste intensity did – actually, together, these three characteristics accounted for more than half of the variability in liking across the foods we tested,” said Rogers.
“Our suggestion is that humans are programmed to learn to like foods with more equal amounts of carbohydrate and fat, and lower amounts of fibre, because those foods are less filling per calorie. In other words, we value calories over fullness.”
The team behind the study, led by Bristol’s Nutrition and Behaviour Group, said the validity of their method was confirmed by, for example, finding a strong relationship between sweetness ratings and food sugar content.
There has been growing concern about the soaring consumption of UPFs across the globe, and UPFs now make up more than half the average diet in the UK and US.
Recent studies have linked UPFs such as ice-cream, fizzy drinks and ready meals to poor health, including an increased risk of cancer, weight gain and heart disease. However, some UPFs such as bread and cereals, are good for health, other research has concluded.