It is not a myth at all. I am like points, I've been the same weight for several years, and while my diet has changed a whole lot, my weight has not.

I can eat a stick of butter and I won't gain a pound (unless the butter weighs a pound..). My body simply won't store the extra energy, it uses what it needs and the rest goes out the end. It is a tad frustrating because I am a bit underweight as well.