It’s a situation that everyone has experienced: You’re hungry and you encounter the smell of food, which then makes you even hungrier. It might seem logical, then, that stronger food smells would lead to eating more food. But a study from the Netherlands, described recently in an article at HealthDay, suggests that the opposite may be true.
Published in the journal Flavour, the study involved ten adult participants who were fed vanilla custard through a tube attached to their mouths. The custard was administered in 30-second intervals, during which participants could stop its flow with the push of a button to choose how much they wanted to eat in one bite. In addition to the tube in their mouths, participants had a device attached to their noses through which the researchers could deliver smells. Each time custard was administered, an aroma designed to signal a creamy, fat-containing dairy product, at either a low or a high concentration — or no smell at all — was delivered at the same time. Each smell variation was used ten times, with the order mixed up, for a total of thirty bites of custard. The total amount of custard that each person ate, according to the researchers, was less than in a standard dessert.
When the researchers calculated how the size of custard bites corresponded with the strength of the smells they delivered, they found that a stronger smell resulted in a smaller bite — both for the current bite, and for the next one. Overall, the strong creamy smell resulted in a 5–10% decrease in bite size; the weak aroma had a barely measurable effect, compared with no smell at all. To explain this result, the researchers speculated that the body may use smell to try to gauge how many calories are in a food, and then to limit intake based on this estimate. While bite size may not always correlate with total intake of a food, the two measures are related — meaning that if a person takes large bites of a particular food, he is likely to eat more of it.
Needless to say, vanilla custard is not necessarily representative of food in general. Since it is sweet and somewhat fatty, and is not chewed in the same way as most of the food we eat, it may represent only one type of food for which the smell–bite size relationship is true. After all, many people find bland foods unappetizing and probably take smaller bites of them than equivalent foods with more aroma and flavor — say, for example, plain oatmeal versus oatmeal with brown sugar and cinnamon.
Do you think you tend to take bigger bites of bland foods, or foods with a more intense aroma and flavor? Have you ever made an effort to change the overall flavor level of your diet, such as by cooking with more herbs and spices? If so, did you notice a difference in how much you ate? Do you find that a healthy diet is more or less flavorful than an unhealthy one? Has this affected your ability to stick with it? Leave a comment below!