"I'm addicted to pizza!" If this phrase flies out of your mouth as you shovel down slices of pepperoni pie, you might be onto something! It turns out, humans are practically hard-wired to crave pizza! Here's an ingredient-by-ingredient breakdown. Courtesy of Quick and Simple Magazine and Dr. Steven Witherly, author of Why Humans Like Junk Food. Let's talk about pizza dough. Why do we love it so much? Humans tend to crave cooked foods - because in the olden days, our ancestors weren't sure if raw foods were going to be poisonous or not. So when we smell a baked pizza, it notifies our brain that the food is cooked - and therefore probably safe to eat. Subconsciously, if we know a food isn't going to harm us, we're going to be drawn to it more-so than food we're not sure about. What about pizza sauce? The acidity in tomatoes causes us to salivate and since saliva helps get food molecules to your taste buds, the "mouth watering" effect from the sauce is going to make a slice of pizza taste especially good. There's the cheese. It contains proteins called caseins - which are one of the best muscle-building nutrients you can eat. However, caseins are also addictive. Which explains why we like to order pizzas with extra cheese! There's a reason why a lot of people like to top their pizza with pepperoni. The fat content increases your production of the feel-good hormone serotonin, which boosts your mood. Basically, pepperoni can help you feel happier. Which may explain why we love to pile it on our pizza!But know this: 2 large slices of pepperoni pizza contain almost 600 calories! You'd have to play an hour of basketball to burn that off! So try to keep your pizza cravings in check.