A whiff of a decadent dessert can whet the appetite, but new research suggests that when it comes to the smell of food, you can have too much of a good thing.
In an odd but clever experiment, Rene de Wijk, a sensory scientist at Food & Biobased Research in the Netherlands, decided to investigate how smell affects the amount people eat. Previously, he and his colleagues had determined that the texture of food (what foodies call mouth feel) alters how much people consume — the more viscous and thick a food is, the less they eat with each bite. And the smaller the bite, the less people consume overall.
So de Wijk wondered what other factors might go into bite size. It matters because when we take smaller bites, we tend to process and swallow food faster, which limits the sensory experience of eating — that includes the way food feels, the way it smells and the flavors it releases on our tongue. The end result may be that we feel fuller sooner and put down the fork.
De Wijk focused on smell because odor is something that can be added or subtracted from food without affecting its other features, like its texture. So he set up a study in which 10 volunteers were hooked up to a pump that dispensed a custard dessert into their mouths, while at the same time a separate pump supplied differing levels of a cream aroma to the back of the nose and throat (it’s certainly not the way most of us eat, but for the purposes of the study, it worked). The participants controlled how much custard they received, which constituted their “bite.”
After 30 trials, de Wijk and his colleagues started to see a pattern. “The stronger the smell, the smaller the bite size,” he says. And it didn’t take much aroma to change the amount people ate. “Our concentrations were very low, hardly detectable,” he says. “So the effect is quite subtle.”
That’s encouraging for weight-loss strategies, since it suggests that even a small boost in aroma might be enough to alert our senses that something intense is on its way to the mouth, and that perhaps we should exercise caution before gobbling it up. “It could be that people are self-regulating, and that with a more intense odor, we take instinctively smaller bites to avoid strong sensations,” says de Wijk.
Of course, food aromas work on multiple levels, and in many cases can trigger hunger sensations and the desire to eat. But if de Wijk’s results hold up, there may be a way to manipulate smell and counteract a heightened appetite by encouraging eaters to instinctively keep their bites on the small side.