And we always thought a healthy diet and plenty of fresh air and exercise could make you fatter. Who knew that sitting on the couch with your feet on the coffee table while burning the equivalent of one Triscuit's worth of calories every 18 hours could do it too? Actually, the study, out of Tel Aviv University, went even further, showing that precursor fat cells turn into actual fat cells faster when subjected to extended periods of "mechanical stretching loads," which they defined, essentially, as sitting around.