Is Plate Size Important?

We know that portion control is one key to eating healthy. It seems like such a simple concept, and there's plenty of research to show that being careful about how much you put on your plate makes a difference in how much you actually eat. But what about the size of the plate? Does using a small or a large plate make a difference in how much you actually eat? The answer is maybe.

In one of my favorite studies, nutritionists arranged an ice-cream social. (American Journal of Preventative Medicine 2006; 31: 240 -243) The dessert eaters were given either a large bowl or a small bowl to use for their ice cream. They were also given either a large or a small serving spoon and allowed to take as much as they wanted. They were then quizzed about how much ice cream they felt they had served themselves and how much they had eaten.

Those participants who were given a larger bowl served themselves about 1/3 more ice cream. If they used a larger serving spoon, they took about 15 percent more. Those who used both a larger bowl and spoon took 45 percent more ice cream than they would have had they used a smaller bowl and serving spoon. Interestingly, only three of those at the party didn't finish their ice cream.

Studies of children, however, have shown that it doesn't matter much what size the plate is when kids serve themselves. In those studies, no matter the size of the plate, and no matter whether they were served or filled their own plates from a buffet, the study subjects pretty much ate the same amount. (Appetite [2007], doi:10.1016/j.appet.2007.04.005)

Other research has shown equally mixed results. In some ways, that's a bit of a relief. I rather like serving food on very large plates at dinner parties, because I think that puts a focus on the foods.

As a side note, there is good research that shows that using a portion-control plate can help diabetics eat less. The Diet Plate is a dinner-sized plate with printed outlines to show the appropriate serving sizes of a meal. There's also a cereal bowl with rings painted on the inside to show serving sizes.

In one study, scientists recruited 122 obese diabetics. (Arch Intern Med 2007; 167:1277-1283) About half were given Diet Plates and bowls and taught how to use them. The other half received their usual care from their doctors and dietitians. All of the participants were told not to eat more than usual between meals.

During the 6-month research period, the group that used The Diet Plate lost significantly more weight. The amount of weight that was lost was pretty amazing, equivalent to a 300-lb. man losing between 5.4 and 17.1 lbs. This is as great as loss as that registered in research on prescription weight-loss medications. So once again, portion control rules, but simply using a smaller plate doesn't seem to help.