cyclonebill / Flickr

One of the things that always surprised me when I was studying in Belgium was that everyone looked like they had stepped out of an Urban Outfitters catalogue, despite consuming nothing but mayonnaise-covered french fries and strong wheat beer.

Everywhere I went—the Metro, the McDo—I saw fawn-like humans. Fawns who smoked a lot of cigarettes, but fawns nonetheless.

In search of Their Secret, one day I watched lunch being prepared by my host sister, who wore size 32 jeans. (In America, it is, how you say, le deux?) She plucked a can of ravioli from the cabinet, plopped a few spoonfuls of it into the kind of bowl one might use to feed a dwarf kitten, and put the rest in the fridge.

The sight was more incredible than the Atomium itself. “She’s actually using the suggested serving size,” I thought. The Belgians were indeed having it all, I learned—it's just that they were having half of it.

Nutrition researchers have long suspected that serving food in small portions and on small plates helps people avoid weight gain. Most people don’t eat only to the point of satiety and no further. To quote Girls’ Adam, most people eat for fun, not for fuel.

A recent review from Cochrane offers what the organization calls “the most conclusive evidence to date” that people do, in fact, consume more of a given food when it’s offered in a larger package or on a bigger plate.

Cochrane is known for compiling exhaustive reviews of studies on a given topic, thereby slicing through contradictory findings and pointing to a clear takeaway. For this review, researchers from the University of Cambridge examined results from 6,711 participants across 61 studies that looked at the effect of portion, package and plate size on food consumption. The authors found that people using larger plates not only piled more food on them, they ate more.

In fact, if Americans could eliminate large sizes from their diets entirely, Cochrane noted in an accompanying release, they would shave up to 527 calories off their daily food intake—enough to lose about a pound a week.

“Helping people to avoid ‘overserving’ themselves or others with larger portions of food or drink by reducing their size, availability and appeal in shops, restaurants and in the home, is likely to be a good way of helping lots of people to reduce their risk of overeating,” Gareth Hollands, of Cambridge’s Behavior and Health Research Unit, said in the statement.

This paper underscores something I wrote about earlier this week: Increasingly, research points to the idea that weight problems can’t entirely be chalked up to a lack of self-control. Environmental factors, such as chemicals, medications, or in this case, gigantic dishware, seem to play a significant role in how big we get.

The researchers say one public policy solution is an end to “value size” pricing, in which larger packages seem like a better deal for the money. (Here’s looking at you, extra-large movie-theater popcorn that’s only a few cents more than the small.)

That’s almost certainly never going to happen, at least in the U.S. Instead, Americans who want to lose weight might want to take a page from the Belgians and eat tiny amounts of some of the fattiest food on earth. Just, you know, don’t take up smoking to compensate.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.