The scientific evidence is clear as can be that cutting calories simply doesn’t lead to long-term weight loss or health gains.We suspect most dieters have realized this by now too. And yet, here they are again, setting the same weight loss goal this year that they set last year.The only people who don’t seem to appreciate this are people who have never dieted. It’s particularly hard for them to believe because it doesn’t square with their own eating experiences.Take Nicky, for instance. She eats sensibly much of the time, with some junk food here and there, but it doesn’t really seem to affect her weight. She’s not a dieter. She is Naturally Thin Nicky, and it’s not surprising that she believes what she sees with her own eyes and feels in her own body. Nevertheless, Nicky has it wrong.The long, strange history of dieting fadsWe are researchers who have been studying why diets fail for a long time. We have seen that diet failure is the norm. We have also studied the stigma that heavy people face, and witnessed the blame game that happens when dieters can’t keep the weight off. From a scientific perspective, we understand that dieting sets up an unfair fight. But many Nickys we’ve encountered — on the street, in the audience when we give talks, and even fellow scientists — get confused when we say dieting doesn’t work, because it doesn’t square with their own observations.