Imagine you are locked up in a hospital room with a bed and plenty of food. What do you think you'd be doing when you aren't sleeping?
Well, some researchers (link) discovered that you'd be eating the food. What a surprise.
The New York Times then saw it fit to report this result as "Lost Sleep Can Lead to Weight Gain", which isn't as bad as the lead given on the front page of NYTimes.com "To Put on Pounds, Just Sleep Less".
Of course, the researchers never proved that sleep deprivation is a cause of obesity. In the original press release, the lead scientist explicitly noted: "Just getting less sleep, by itself, is not going to lead to weight gain. But when people get insufficient sleep, it leads them to eat more than they actually need."
It's a scandal that the prestigious paper would write a headline that directly contradicts what the researcher said.
I also have a problem with the link between insufficient sleep and eating more. Here is their description of the experiment:
For the study, researchers monitored 16 young, lean, healthy adults who lived for about two weeks at the University of Colorado Hospital, which is equipped with a “sleep suite” for controlling sleep opportunities — by providing a quiet environment and by regulating when the lights are on and off — and a sealed room that allows researchers to measure how much energy participants are using based on the amount of oxygen they breathe in and the amount of carbon dioxide they breathe out.
All participants spent the first three days with the opportunity to sleep nine hours a night and eating meals that were controlled to give participants only the calories they needed to maintain their weight in order to establish baseline measurements. But after the first few days, the participants were split into two groups: one that spent five days with only five hours to sleep in and one that spent five days with nine hours of sleep opportunity. In both groups, participants were offered larger meals and had access to snack options throughout the day ranging from fruit and yogurt to ice cream and potato chips. After the five-day period, the groups switched.
The participants who were forced to sleep less spent more time eating.
The NYT column actually described another study which I think holds more promise. It tries to connect sleep deprivation with fat cell biology. The sample size is really tiny, and a lot more work is needed.