But they also found obese participants tended to keep more food visible in the places they spent the most time compared to non-obese people. If the bedroom was one of their favorite places at home, then snacks were also usually there in plain sight. In other words, food was almost always close at hand for the obese individuals. "It doesn't take a big leap of faith to say if you're spending most of your time where there's more food sitting out to see, that's going to make it harder not to eat," Emery says.
Emery thinks depression might be one reason people keep snacks close-by. And he says obese people are more likely to be depressed than non-obese people, maybe because of the stigma attached to obesity. He saw this in his study participants, too, and his obese volunteers also worried about food more.
Put all that distress together, he says, "the picture you see is that the obese individuals thinking about food more, not feeling good about themselves." And that might lead some people to keep more food around to comfort or reassure themselves.
This isn't the first time researchers have noticed that your environment may, in some part, shape your weight. "It's really supportive of a line of research out there that finds eating behaviors are really influenced by environment," says David Just, a behavioral economist at Cornell University who was not involved in the study. In other research, scientists have found that people who kept cereal out in the open were often about 20 pounds heavier than people who kept cereal behind closed doors.
But studies like these are just associations and don't prove causation, says James Hill, a physiological psychologist at the University of Colorado who was not part of the study. "[Emery's study] doesn't tell us much about why people are obese or how to help them lose weight." All it does is point out a few things that seem to be different among people who are overweight and people who aren't, he says. Leaving a bag of chips by your favorite armchair doesn't necessarily mean that habit will lead to obesity, just as being obese might not lead you to have chips by your side. Hill says until we know more, doling out medical advice based on these correlations "would be a mistake."
Emery agrees that's a big limitation of the study. It's just observational and can't say whether having certain food habits leads to weight gain or if it's some other thing, like depression or perhaps obesity itself, which leads to these habits.
"Potentially, it can go both ways," Emery says. But he says the work has steered him towards answering a very basic question: "Can we influence our behavior by changing environmental features?" He wants to see if people will eat less or eat healthier just by reorganizing their spaces so they aren't outfitting their favorite spots with their favorite snacks.
"If we're able to pull off those types of studies ... and find the causal link it might suggest, you know, we redesign home layouts so people end up eating less often and eating healthier foods more often," Just says. "But this is a basic first step."
They haven't done any experiments yet, but Just thinks Emery's observations create a useful roadmap for the kind of investigations that could tell if food-laden environments really do contribute to obesity or if it's the other way around. Until then, he says it might be a little hasty to start dishing out medical or even home remodeling advice based on this study. Although, he admits, "My own house... we had cereal sitting out sometimes, and we sorta stopped."
Angus Chen is a journalist and radio producer based in New York City. He's on Twitter: @angrchen