Why do we always have room for dessert?

Live Science quotes Leonard Epstein in an article discussing why we tend to feel hungry again after being presented with a dessert. "Part of the reason why people stop eating a meal is that they're tired of the food; they've eaten it [and] there's no more stimulation," Epstein said. "They know exactly what it tastes like. But if you introduce a new flavor, smell or even texture into the mix, it's easy to overcome that feeling of 'Oh, I'm full.’"