I read the article with interest, but was left with more questions than answers. I wish they had included another test group (or would in the future), that being "sedentary standing." i.e. set the computer up on a counter and stand in front of it for the same time as is being measured for sitting. Their "stand up and putter" suggestion, to me, says "stand up and walk around" which equals exercise (very mild, but exercise). If you stand up and walk around an extra four hours a day it would make sense you would loose weight based on extra calories burned!