Nonfat eggnog, sugar-free cake, mashed cauliflower instead of mashed potatoes. Anything that's a "light" version of something you love...skip it! (Unless you really like mashed cauliflower, of course, then load up your plate.) All these foods will do is make you feel like it's OK to eat more because they're ~healthier~, Ott says, noting that this is called the "halo effect." In addition to the halo effect, none of these foods are as satisfying as the real thing, she says, so you might eat three slices of sugar-free cake and not feel as satisfied as you would have if you just went with one full-sugar slice. "Enjoy the food as you want to, and just have a bit less of it," Matheny says.
The halo effect can also come into play when eating home-cooked calorie substitutes, like pie with low-calorie sweetener instead of sugar. "By restricting at those meals, it could trigger your brain to think, 'Oh, well I was really 'good' at that meal, so I deserve XY and Z later,' and that can lead to overeating later on. So just by allowing yourself to have what you actually want, versus withholding at that meal, you're probably less likely to gain weight," says Ott.