High-cal splurges are almost always psychological and behavioral, not biological. Three of the most common reasons we splurge on comfort foods include:
They provide a bridge to the past: Maybe you had pizza with your family every Sunday when you were growing up or ate Cracker Jacks at the ball game. Your urge to splurge may not be linked to childhood, but it is often related to a food that made you feel good at one point in time.
They have good mouthfeel: Ever wonder why you can't take just one bite of that fudge-nut brownie? Mouthfeel, the physical and chemical interaction that happens in your mouth, may have something to do with it. Sweet and fatty foods usually have a favorable consistency and turn on your taste buds to make you crave more.
You're on a low-fat diet: If you're eating less fat, there's a good chance you'll crave salty comfort foods.