Although the plates and bowls that were being used were small, within 3 servings I was already feeling quite stuffed. By 4 I was completely done, the foods weren't even particularly of the filling or heavy variety. I consciously knew of the tactic, but my brain still perceived it as eating more food than it was in reality.

 In practice, the Delboeuf illusion has benefits for those looking to lose a bit of weight and for restaurants looking to cut down on costs.