Researchers have used this technology to attempt to better understand the parts of the brains that get activated by different systems and pathways. Some researchers now theorize that there are two pathways that show how brain activity relates to feelings of hunger:
- Homeostatic: this is basically the control mechanism our bodies use to manage our energy balance. They largely rely on hormones to either stimulate or suppress hunger depending on whether we have excess energy stores (i.e., have eaten enough). Leptin levels are elevated to suppress hunger while grehlin levels are elevated when we need food. Said differently, this system was designed to help us figure out when we need food or not. It is not to say that the system works perfectly in guiding people to their swimsuit-fantasy selves, but it generally works on some level.
- Hedonic: appropriately named, the hedonic system is theorized to stimulate people to consume "highly palatable" foods (and drugs) through dopamine release through something called the mesolimbic dopamine pathway. Basically, when you see a picture of chocolate cake your brain goes fuzzy. And you eat. Or you really want to eat. Badly.