Science Says Using Smaller Plates Won't Help You Lose Weight

You can't trick your appetite so easily, after all.

If you're on a diet, you know that eating healthy and exercising isn't necessarily enough. Portion control can often be the key to the battle of the bulge, and with the massive portions that restaurants tend to serve in the US, it's not always easy. Anyone who's been to Italy knows that a plate of pasta there tends to be significantly smaller than in the US, which is one of their secrets to staying slim.

For years, one of the easiest weight loss hacks suggested by experts has been to serve food on smaller plates. The trick is based on the Delbouef illusion, which found that when you place two identically-sized black circles side by side, but surround one with white space, the one that is encircled appears larger. The theory, then, is that if you arrange your meal on a smaller plate, it will seem like a heftier helping than if you put the same serving on a large one, and will therefore help trick your brain into eating less food.

Whether or not this is effective is a matter of debate in the scientific community, and a new study published in the journal Appetite claims it's a myth. When researchers at the Ben-Gurion University of the Negev (BGU) tested the Delbouef illusion on people, they found that, as has previously been noted, they did indeed perceive identical circles incorrectly when one of them was surrounded by an annulus. However, this did not transfer over to food, at least not among those who were hungry. Compared to those who had eaten recently, people who hadn't eaten for three hours were more likely to correctly identify the size of pizza served on larger and smaller trays, indicating that hunger stimulates analytic processing that isn't so easily fooled by the illusion.

"Plate size doesn't matter as much as we think it does," Dr. Tzvi Ganel, head of the Laboratory for Visual Perception and Action in BGU's Department of Psychology and lead author on the study, said. "Even if you're hungry and haven't eaten, or are trying to cut back on portions, a serving looks similar whether it fills a smaller plate or is surrounded by empty space on a larger one."

Not only does this indicate that serving food on small plates won't help curb the amount you eat at home, it also suggests that restaurants aren't doing much to abate adult obesity by switching to smaller plates.

"Over the last decade, restaurants and other food businesses have been using progressively smaller dishes to conform to the perceptual bias that it will reduce food consumption," says Dr. Ganel. "This study debunks that notion. When people are hungry, especially when dieting, they are less likely to be fooled by the plate size, more likely to realize they are eating less and more prone to overeating later."

But before you break out your big bowls, it's worth noting that other studies have found that smaller plates can curb consumption under certain conditions. A 2016 study that analyzed 56 previous studies on this issue claims that reducing the diameter of a plate by 30 percent does lead to a 30 percent reduction in food intake. However, this is only the case if someone is serving themselves and if they are not being observed by other people.

Even with the BGU study, the smaller-plate trick can still work if you aren't ravenously hungry every time you eat a meal, which is perhaps why eating several small meals a day is still considered healthier than starving yourself and inhaling a large dinner.

And if you're looking for a way to eat less and enjoy your food more, check out why Science Says This Simple Trick Will Make Any Food Taste Better.

To discover more amazing secrets about living your best life, click here to sign up for our FREE daily newsletter!   


Diana Bruk
Diana is a senior editor who writes about sex and relationships, modern dating trends, and health and wellness. Read more
Filed Under