Less time to cram more into a day...which often times leads to less sleep for most.

The average american now sleeps one or two hours less per night than she/he did 40 -50 years ago.

A study tracked more than 68,000 women (University of Chicago where there are numerous studies on sleep and obesity).  those who slept fewere than five hours a night were 32 percent more likely to gain roughly 30 lbs over the next 16 years than those who slept for at least 7 hours a night. 

When folks were allowed to sleep for just 4 hours a night for two nights, research findings showed more ghrelin (hormone that increases appetite) and less leptin (hormone that is the sense of satisfaction) than when folks were allowed to sleep for nine hours.  Those that were short sleep were hungrier than those who had the longer sleep.

Sleep restriction is associated with fight or flight response...stress, so other hormones are affected affecting glucose metabolism and insulin resistance.

So try to get at least 7.5 hours of zzz's a night.  Your body will thank you.