Does plate size matter?

The way to lose weight is by taking in fewer calories than you burn, but that’s easier said than done. One potential way to make energy intake reduction easier is to reduce plate size—a technique that’s suggested by reputable sources like the United Kingdom’s National Health Service^[1]. If someone uses a smaller plate, they may serve themselves smaller portions, and this will cause them to eat less overall. Or, perhaps the effort of having to refill a small plate will act as a minor barrier to taking in more food.

While these are nice stories that seem to make sense, stories aren’t science. Whether small plates lead to reductions in energy intake that can in turn lead to weight loss is a hypothesis that can and should be tested empirically. And it has; there have been enough studies in this context to feed three) meta-analyses^[2][3][4] on the topic. But, as some of these meta-analyses’ authors have noted, there is a problem: a sizable number of the studies that went into the analyses are of questionable quality (e.g., it’s unclear if they were randomized), or enroll people that don’t represent the general population well (e.g., children^[5]).

In order to determine whether plate size would actually affect food intake for most people, high-quality randomized controlled trials have to be conducted with participants who are more representative of the general population. Until recently, no such trial existed. The study under review aimed to fill this gap.

It’s plausible that eating off of smaller plates could lead to less food intake, which in turn could help with weight loss. However, many of the studies examining whether plate size actually affects food intake are of questionable quality or have recruited people that don’t represent the general population. The study under review was designed to examine the issue with a high-quality study design and people who are more representative of the general population.