There are two hormones involved in suppressing and raising your appetite: grehlin and leptin. Ghrelin is the so-called “hunger hormone.” It’s responsible for stimulating hunger and subsequently letting you know when it’s time to eat, increasing energy stores, and depositing fat. The hormone is released from cells in your stomach, then travels and interacts with your brain’s physiological eating center (the hypothalamus) and pleasure centers.
Naturally, your ghrelin levels will fluctuate throughout the day, rising before a meal and plummeting after, so as you'd expect, it's a key hormone for guys trying to burn fat and manage their weight. Ghrelin increases your appetite, slows metabolism, and decreases your body’s ability to burn fat, according to the Obesity Action Coalition—making it a key player in the battle for weight loss.
Leptin, on the other hand, is the “stop-appetite hormone” that signals your brain to reduce its appetite and burn more calories. It’s produced in fat cells and helps mediate weight loss by decreasing your hunger, food consumption, and increasing energy expenditure. Contrary to what you might expect, though, obesity is linked to unusually high concentrations of hunger-blocking leptin. Researchers believe these high concentrations make the receptors for leptin inactive, impairing its ability to eliminate excess fat. In essence, such high amounts of leptin essentially desensitize the body to it, meaning you can't take advantage of its signaling.
Feel like you’re constantly fighting a losing battle with your hunger? We’ve got the most common reasons you’re raising ghrelin (your hunger hormone) without even realizing it. Identify your problem habits, then biohack your appetite for good.