The function of your body’s hunger hormones is just one example of how complex weight really is. At any given moment, your hormones affect everything from your appetite and energy to the quality of sleep you get at night.
Though your weight is impacted by a number of different hormones as well as other factors, two hormones in particular – Ghrelin and Leptin – work together to affect your hunger and calorie intake. We take a deeper look into these two key players below.
Two Main Hunger Hormones
Ghrelin and Leptin both appear to be direct in their effects on eating and weight. Many believe that the actions of these “stop and go” appetite hormones are straightforward and that one is “good” and the other is “bad,” but it’s really not that simple.
Ghrelin, the “Go” Hormone
Ghrelin, otherwise known as the “go” or hunger hormone, is responsible for stimulating hunger and tells you what to eat. It is released primarily from cells in your stomach and travels to your brain. There, it interacts with both the hypothalamus (your brain’s physiological eating center) and the brain’s pleasure centers to arouse hunger.
Ghrelin levels naturally fluctuate throughout the day, rising before a meal and plummeting once you’ve eaten. Because it stimulates the brain and controls appetite, Ghrelin also slows your metabolism and decreases your ability to burn fat.
Despite what you may think, Ghrelin levels are actually lower in people with higher weights. One explanation is that excess weight may increase sensitivity to Ghrelin, so not as much of it is needed to stimulate hunger.
Leptin, the “Stop” Hormone
On the other hand, we have Leptin, otherwise known as the “stop” or fullness hormone. Leptin is produced in fat cells and plays a role in weight regulation by signaling the brain to reduce appetite and burn more calories. As Leptin decreases your hunger as well as how much you eat, it also increases energy expenditure, making you want to be more active.
Obesity is linked to unusually high amounts of leptin. Some research suggests that these large amounts make the receptors of leptin inactive and hurt the very thing that should eliminate excess fat. So although plenty of Leptin is being produced, the body’s appetite suppression system isn’t functioning as it should.
We know that the body’s hunger hormones, Ghrelin and Leptin, play a role in everyday eating and weight-loss – but we don’t know how much. They are part of a chain of other physiological processes that also affect our weight. More research is being done into hunger hormones to learn more about weight regulation and develop science-based obesity treatments. For more information on this topic, view this article from the Obesity Action Coalition.
What we know for sure is that weight-loss is complex and not as simple as “eat less, move more.” Talk with your healthcare provider if you have questions about whether your hormones may be affecting your weight.