According to The Salt, NPR's food blog,
To isolate aroma from other food sensations, the scientists set up a machine that delivered vanilla custard into the 10 study participants' mouths. They could control the size of the bite delivered. Then a cream aroma was piped into the peoples' noses, at varied levels of intensity. People had about 5 percent less in each bite when the cream aroma was stronger.
These findings aren't conclusive, as this was a very small study published in Flavour, a new research journal. But an interesting thought!
Read More: Intense Aromas Lead to Smaller Bites at NPR