I don’t know why tableware sets love to include gigantic plates, but somehow we always end up with a few large plates we never use. They seem more for serving a group than for one person. We tend to use the smaller plates when we eat.
The reason is that you can fill up a small plate and it will look like a decent amount of food. But put that same amount on a big plate and your mind will want to add more, because the portion will seem so small.
This is a great way to keep yourself from eating too much at once.
There have been studies on it too! So it’s not just me saying it.
People base their portion size on how it looks relative to their plate, bowl, cup, and utensils. And so the bigger the dinnerware, the bigger the portions. Additionally, most people “clean their plates,” mindlessly eating until no food is left, rather than until they are physically full. When people use smaller dinnerware, their portions are also smaller, so “cleaning your plate” actually results in eating less food than when people use larger dinnerware.
Wansink, B., van Ittersum, K., Painter. J.E. (2006). Ice cream illusions: Bowls, spoons, and self-served portion sizes. American Journal of Preventive Medicine, 31, 240–243. doi: 10.1016/j.amepre.2006.04.003.
The Delboeuf illusion helps explain some of this mind-eye trickery. That black circle on the big plate looks way smaller than the one on the right.