The Shape of a Glass Can Influence How Much You Drink

It’s not necessarily logical that how much food or drink you consume should depend on what dish the food or drink is served in, but people’s dietary habits aren’t always logical.

In fact, a running theme in food psychology research is that environmental cues, known as nudges, can push people’s eating and drinking behaviors in one direction or the other.

I’ve written before about how this idea applies to the age-old challenge of getting children to eat their vegetables. As a series of experiments showed last year, kids apparently eat larger servings of vegetables when the vegetables are served on plates that depict … large servings of vegetables. The messaging there isn’t so subtle, but it seems to work.

Now a team of researchers has come out with the adult version of that study, which looks at whether people’s drink consumption varies depending on whether they drink from wine flutes or martini glasses.

It might seem like a trivial question, but don’t laugh – it’s apparently important enough to attract the efforts of five researchers at Cambridge University spanning the fields of behavioral health, emotional health, and cardiovascular epidemiology.

The motivation for focusing on how glass shapes influence drinking behavior is that if people drink less from certain types of glasses, serving up unhealthy drinks in those glasses could theoretically “nudge” people away from unhealthy drinks, or at least get them to consume less.

So who ultimately won the battle of wine flutes versus martini glasses?

When the researchers served people soft drinks in those glasses, they found that although people with the two types of glasses drank for the same amount of time, those with martini glasses consumed a greater quantity. They did so primarily by getting a strong head start, drinking more prolifically in the first half of the time period.

Examining the drinking “techniques” used by both groups, the researchers found that wine flutes prompted people to purse their lips more while drinking. That suggests a possible reason that people with wine flutes drank less: compared with drinking from an outward-sloping martini glass, drinking from a straight-sided wine flute might simply be harder.

A key takeaway, according to the researchers, is that “switching to straight-sided glasses” could help “reduce consumption of health-harming drinks.”

Personally, though, I’m a little skeptical of whether that will catch on. As much as I believe in following science, asking me to drink a martini out of a wine flute might be a bridge too far!

Image: Flickr/Martin Howard