Eating for nourishment and pleasure doesn’t have to be mutually exclusive, but sometimes being hungry doesn’t even seem to be the reason you’re reaching for a snack. Maybe you’re bored, maybe you saw an ad for pizza, or maybe it’s a group hangout or celebration — like, your best friend’s birthday.
Those kinds of environments can influence your eating habits, but there’s also something happening physiologically when it comes to hunger. Certain hormones in your body are in charge of signaling to your brain that it’s either time to eat or time to put the fork down. And much like other hormones in your body, hunger hormones are affected by so many factors, from your diet to environment to sleep.
Ahead, we’re dissecting the two most important hunger hormones, breaking down what happens when they get off balance, and giving you helpful tips to recalibrate for hormone harmony.
What Are Hunger Hormones?
Hunger hormones typically refer to ghrelin — which signals hunger — and leptin — which signals satiety or fullness. Ghrelin acts like a guard to make sure blood sugar doesn’t fall to hazardously low levels, and leptin is the monitor to make sure you’ve had enough. The goal is equilibrium, which is why the two hormones work in tandem. As one rises, the other is dropping, known as a negative feedback loop.
But hunger hormones aren’t acting solo. They’re part of a comprehensive conversation with your gut and brain; these hormones emit signals, and based on the appropriate feedback, your brain’s hypothalamus ultimately tells you what to do. For example, if the message is that it’s chow time, your gut prepares by increasing saliva and secreting digestive enzymes and other elements that’ll help you digest.
What is Ghrelin?
Produced by the gut, ghrelin stimulates feelings of hunger and food anticipation by inhibiting the output of insulin, a hormone that allows your cells to use or store blood sugar, and communicating with your brain that it’s time to eat. (In fact, research has shown that because of ghrelin, your hypothalamus stores memories of just how available food is in a particular environment). Ghrelin follows a fairly regular schedule, peaking roughly every four hours, which aligns with eating three meals a day.
But its role is more nuanced than cueing you for breakfast, lunch, and dinner. Ghrelin affects dopamine levels and your brain’s reward system, encouraging behaviors that’ll lead you to food — especially high-calorie options rich in sugar or fat. This was important when food was generally more scarce, as a way for your body to load up on calories while they’re available. On the flip side, it can also lead to overeating well after you’re full.
What is Leptin?
In contrast, leptin is a hormone that tells your body (by way of your brain) that you’re full. In fact, it works by inhibiting the effects of ghrelin. Unlike ghrelin, which stems from the gut, leptin comes from adipose tissue, which is connective tissue that stores fat. Once your body recognizes that fat stores are sufficient, a signal is sent to the brain so ghrelin can step in.
How to Balance Your Hunger Hormones
Our hunger hormones are the ones communicating with our brains, but we can communicate with our hunger hormones to send the right message. Here are a few ways to achieve hunger hormone balance:
Fill Up On Protein
Studies have shown that protein reduces ghrelin, keeping us full, satiated, and not reaching for snacks shortly after our meals. Whether you prefer meat, eggs, or plant-based options like tempeh, make sure to load up your plate. (One study found that brown beans, specifically, can significantly decrease ghrelin and increase leptin.)
If you need to stimulate your appetite, you might want to lace up. Research from UT Southwestern showed that HIIT workouts nearly double the concentration of ghrelin. Even more, ghrelin actually boosts the ability to exercise longer, too.
Get Enough Zzz’s
Compare a day of eating after feeling well-rested vs. sleep deprived. You probably noticed a difference. The former might be filled with whole foods and nutrient-dense meals, while the latter might be a snack free-for-all. Studies have shown that sleep deprivation can increase ghrelin and decrease leptin. Hunger hormones aside, a lack of sleep can affect your motivation to cook and instead look for sugar-heavy snacks that might give you a quick fix but lead to an energy crash later.
RELATED: The Ultimate Guide to Sleep
It’s no secret that stress impacts our health — and that means hunger hormones, too. Scientists have found that ghrelin levels rise following stress, but while some think it’s because of stress, others believe it’s a by-product to help us cope with that stress. Regardless, it can lead to over-indulging and throwing the delicate balance off-kilter. Keep in mind that there isn’t one way to de-stress. Here’s a helpful guide on how to reduce stress based on your personality.
Achieving Hunger Hormone Harmony
Although ghrelin and leptin operate on auto-pilot to some extent, there are things you can do to nourish a beneficial, health-boosting balance. Focus on a whole food diet rich in protein, move your body regularly, give your body rest when it needs it, and make time for self-care that mitigates the effects of stress, whether that’s fitness, a face mask, or something as seemingly simple as walking your dog. Your body has all the communication it needs— you’re just encouraging it to be its best.