One-third of U.S. adults are obese, and another third are overweight, according to data recently published in the Journal of the American Medical Association. Marketing scholars Naomi Mandel, Andrea Morales and Steve Nowlis have been investigating what influences our decisions about diet. Knowledge@W. P. Carey spoke with Professor Morales recently about two of her studies. One investigated those tempting 100-calorie snack packs, and the other looked at whether your dining companions have any effect on your food selections. The results may surprise you. (13:25)