There's something particularly appealing about a buttery croissant. But what is it about certain foods that makes us want more, even before we've taken the first bite?
A new study from the University of Bristol suggests the combination of fat and carbohydrates may play a role. Researchers found that people not only liked foods containing roughly equal amounts of calories from fat and carbohydrates more than foods made up mostly of one or the other, but also expected to need larger portions to feel full. The findings, published in the journal Appetite, suggest that what's in our food may influence how much we think we'll want to eat.
The researchers conducted two online studies involving 298 adults in the United States and United Kingdom. Participants viewed photographs of different foods and rated how appealing they looked, how much they wanted to eat them and how much they thought they'd need to feel comfortably full.
The foods fell into three groups: those made up mostly of fat, those made up mostly of carbohydrates and those containing a more even mix of the two. Researchers selected foods with similar calorie densities to help make the comparisons more meaningful.
Across both countries, the results followed a similar pattern. Foods combining fat and carbohydrates were rated as tastier and more desirable. Participants also expected to need larger portions of these foods to feel satisfied.
Among American participants, for example, the estimated amount needed to feel comfortably full averaged about 228 calories for foods combining fat and carbohydrates, compared with approximately 201 calories for foods made up mostly of fat or carbohydrates.
That difference may seem small, but it raises an interesting question: Do we find these foods especially appealing because we expect them to be less filling, or do we expect to eat more simply because we like them?
The researchers don't yet know.
Previous studies have suggested that combining fat and carbohydrates can make foods especially appealing. This research adds another piece to the picture by showing that the combination may also influence expectations about fullness.
But there's an important distinction between expecting a food to be less filling and actually feeling less full after eating it. Participants never tasted the foods during the experiments. Their answers were based entirely on photographs and their own expectations.
Researchers also couldn't fully separate the effects of fat and carbohydrates from other characteristics, such as fiber, sugar and protein content, which may have influenced how participants viewed the foods.
Two researchers received partial support from the National Institute for Health and Care Research Bristol Biomedical Research Centre in the United Kingdom.