Increasing food aroma can reduce bite siz by 5-10%, a team of scientists at the Top Institute Food and Nutrition in the Netherlands found. Led by Rene de Wijk, the group conducted its study by presenting participants with a vanilla custard dessert, and then delivering different strengths of vanilla aroma to participants' noses as they ate. Smaller bites were taken while the aroma was being delivered, and subsequent bites were also smaller.
The group published his findings in peer-reviewed journal Flavour saying that combining this kind of aroma control with controlled portions could lead people to feel full faster, thereby eating less. They also speculated that this could explain why we take smaller bites of unfamiliar or disliked foods.