While I've had a full day of presentations, I think my favorite topic of the day has been sleep, circadian rhythms, and metabolism. I suppose it could be because this is the issue most relevant to my current lifestyle. As an undergraduate student, twice a year the dreaded finals swing around and you find people living in the library and barely sleeping. These same students, afraid to waste precious
Well I'm not saying that the Sleep Conference is my personal answer to this question, but there has been quite a bit of recent research linking sleep deprivation with increased hunger, caloric consumption, and (in the end) weight gain. What I found most interesting was that one study (which I believe came out of this link) showed that sleep deprived participants did consume more calories, but statistically consumed less calories per waking hour than non-sleep restricted participants. This indicates to me that caloric intake isn't the whole story, and perhaps metabolic rates are shifted because of the lack of sleep so that the calories consumed are not efficiently put to use.
Mind you, this is just my take on a particular presentation and I suggest checking out original sources such as this to get the full story. Please feel free to chime in on the comments below as well!