Well, regarding the study in the OP, I've been losing some weight recently, even while still eating McDonalds and such. A triathlete friend of mine told me about an application called myfitnesspal, and I started using it. I'd always heard tracking your food and calories was helpful, but before these new apps getting the calorie count for foods was a major PITA. But using this app I've been able to drop 14 lbs. Still got about 30 to go. But I eat McDonald's, pizza, Taco Hell, etc. as well as healthier prepared at home foods and restaurants like Panera and Carrabbas. Basically as long as the calorie count stays below my target for losing a lb. every couple of weeks, I'm good. Doesn't matter what the food is. And as ElizabethT says, if I do some exercise or physical labor I get to eat some additional calories.