There’s a very straightforward, biochemical reason why we love our fatty, savory, or sweet foods so much. Once you know how your brain will react when it is seduced by junk, you can make a rational decision about what to do about it. From Women, Food, and Desire.
These rich substances release opioids (which are as dreamy and druglike as they sound) into our bloodstream, and when these chemicals bind with the receptors in our brain, we experience an intense sensation of pleasure, maybe even get a little high. When we experience pleasure, a desire is met and we feel good. Though this happy sensation may only last for a short time (even just for the moments that we’re actually ingesting something, such as a piece of sugary candy), the memory of that experience gets stored in our brain circuitry. The next time we see the source of that pleasure, a craving may be activated.
Interestingly, researchers have shown that we may crave the source of that pleasure “hit,” even when it’s well out of sight, because those of us who diet and deprive ourselves of certain foods can conjure up those forbidden treats, and just thinking about them can trigger a mighty craving. In other words, dieters can actually fantasize their way into full-blown cravings, just by equating the lack of something they perceive as being desirable or pleasurable. (For example, there’s that almond tart, sitting behind the glass at the bakeshop around the corner, the one you’ve been thinking about for the past three days. Or there’s that chocolate soufflé on the menu at the restaurant where you will be meeting your friend for dinner next week. Just thinking about that dessert makes your mouth water whenever you look at your date book and see the name of the restaurant that features it.) The power of suggestion is so potent that even just thinking about foods can trigger a craving. Late-night television advertisers know this.
Cravings affect not one but several key parts of the brain, making them very difficult to pin down. The hippocampus, which processes and sorts sensory data like smell, taste, and texture, stores this information as short- or long-term memory. The insula, which frames the brain, processes your physical status (whether you are hungry, thirsty, tired, or cold) and cues you about what you need socially. The caudate nucleus is the core of pleasure at the center of your brain, which controls the release of dopamine. This is the reward center of your brain that feels so well cared for when you eat something sweet and buttery and suddenly feel comforted. Dopamine is the “orgasm” hormone, the one that makes having sex so fantastic, taking drugs so risky, and overindulging in the wrong foods so easy.