Picture this: you’re playing a video game where the goal is to design an organism that can survive and reproduce for thousands of generations. It needs energy to survive, so it has to eat, but it’s not quite that simple.
The challenge is, how do you program it to eat enough without overdoing it? Too little, and it starves. Too much, and its extra weight could be a liability in avoiding predators and other dangers.
Nature came up with a genius solution to this problem: hunger hormones.
These tiny chemical messengers are like the game’s code, running in the background to balance hunger, satiety, and energy storage. They’re the reason you feel ravenous when your body needs fuel and why you (ideally) stop eating when you’ve had enough food.
Sure, the science behind them is mind-blowingly complex, but the feelings they create are simple.
Hungry? Go eat.
Full? Stop. (Oh, and maybe pile on a little extra, just in case, because life’s unpredictable, right?)
In other words, hunger is your body’s way of signaling that it needs more energy and nutrients to function optimally. And while hunger feels like, well, just a feeling, it’s actually a complex interplay of hormonal signals, brain activity, and external influences that drive when, what, and how much you eat.
Your body relies on hunger hormones to regulate appetite and maintain energy balance. When they work well, you don’t have to think about how much or how often to eat — you consume the right amounts naturally.
Unfortunately, factors like poor sleep, chronic stress, ultra-processed foods, and erratic eating patterns can disrupt these signals, leading to persistent cravings, overeating, and difficulty managing weight.
In this article, I’ll explain the science of hunger, delve into the key hunger hormones, and discuss lifestyle strategies for regaining control over your appetite. Understanding and optimizing these internal signals can reduce cravings, maintain a healthy weight, and support long-term well-being.
What Are Hunger Hormones?
Hunger hormones are biochemical messengers that regulate the body’s appetite, satiety, and energy balance. They work to create “negative feedback loops” that trigger you to eat when you need energy and stop when you’ve got enough — like a thermostat that turns the heat on when it senses cold and turns the heat off when the room temperature gets warm enough.
Hunger hormones ensure that your body gets the nutrients it needs in the proper amounts and on the correct timetable while maintaining your weight within a healthy range.
Several different types of hunger hormones work together to create this feedback loop. The main ones are ghrelin, leptin, insulin, cortisol, peptide YY, and cholecystokinin. Let’s look at each of them.
Ghrelin
Ghrelin is produced primarily in your stomach and tells your brain it’s time to eat. In healthy people, ghrelin levels follow a circadian rhythm, rising around meal times to get you to the table and decreasing after eating, so you push away before you overeat.
If your ghrelin levels are chronically elevated, you’ll probably feel hungry all the time — even if you’re stuffed — and will, therefore, gain weight. Two factors that increase ghrelin concentrations are sleep deprivation and stress, which is one reason that missing sleep and feeling anxious are both linked to overeating.
Interestingly, when fat stores drop, the body responds by increasing ghrelin to stimulate hunger, which is a key reason weight regain is so common after dieting.
Ghrelin also regulates the activity of growth hormone, which makes sense because once you’re triggered to eat, it’s your growth hormone’s job to turn some of those nutrients into useful parts of you while balancing energy requirements.
Leptin
Leptin is known as the satiety hormone. It’s produced in the small intestine and adipose (fatty) tissue. By signaling fullness to the brain, it helps regulate long-term energy balance and body weight.
Some researchers see obesity as the result of leptin resistance, meaning the brain no longer responds to leptin signaling. This leads to persistent hunger despite the body’s high energy (fat) stores.
Insulin
Insulin, which is secreted by beta cells in the pancreas, deals with glucose control. When you eat, the carbohydrates in food get dumped into your bloodstream and then travel to all the cells of your body (where, ideally, they are processed into energy). Insulin determines the rate of that conversion, making sure your blood sugar doesn’t get too high or too low and keeping your energy levels within a healthy range.
When your blood sugar levels are high, more insulin is released to help your body store glucose in your muscles. When those muscles have taken in all the glucose they can handle, the rest gets stored in your liver. Once that’s also at capacity, the excess glucose gets dumped into adipose tissue, where it’s turned into fat for long-term storage.
Over time, if insulin levels remain chronically high due to frequent spikes in blood sugar, your cells may start becoming resistant to its effects — forcing your body to produce even more insulin to get the same job done, which can contribute to insulin resistance and metabolic dysfunction.
Insulin is a hunger hormone because unstable insulin levels can trigger food cravings.
Cortisol
Cortisol is produced and secreted by your body’s stress system, consisting of three glands: the hypothalamus, the pituitary, and the adrenal (together known as the HPA axis).
Cortisol comes from cholesterol and is the body’s main stress hormone, flooding your body when you need to convert stored energy into instant alertness and movement quickly. But it’s a lot more than that, impacting just about every system in your body.
Cortisol is a hunger hormone in that it stimulates appetite and makes you especially tempted by very palatable foods (fatty and sweet desserts, for example). This makes sense because stress is a prediction of danger, which might mean a need for urgent action or limited access to food in the immediate future. In such circumstances, it’s smart to grab some sweet or calorically dense food immediately — just in case you need a quick burst of energy to fight or flee or to store fat for an impending period of scarcity.
Peptide YY (PYY) & Cholecystokinin (CCK)
These hunger hormones are released by the gut and promote satiety after meals when the gut says, “OK, full now! Turn off the food chute.” Peptide YY and Cholecystokinin (affectionately known as PYY and CCK) are stimulated specifically by the presence of nutrients, especially fat, in the small intestine.
They’re the opposite of ghrelin, which increases when food stores are low and says, “Time to eat.”
Health Benefits of Keeping Hunger Hormones Balanced
The more we learn about these hunger hormones, the more we discover they’re important in many other bodily processes and systems. Let’s take a look at some of the ways hunger hormone balance affects things other than appetite.
Heart Health
Hunger hormones can impact heart health, but in ways that are still not fully understood. Leptin can act like a double-edged sword: higher levels are linked to increased risks of heart issues like high blood pressure, but it can also help the heart by improving metabolism and preventing harmful fat buildup.
Whether leptin helps or hurts appears to depend on overall health status. High leptin levels are often found in people with heart issues, diabetes, and related conditions, where it can cause inflammation that harms the arteries. In healthy folks, however, leptin may have protective effects.
Type 2 Diabetes
People with type 2 diabetes and obesity often develop leptin resistance, which disrupts the brain’s ability to regulate appetite and energy balance. Normally, leptin signals that fat stores are sufficient, reducing hunger and promoting calorie burning. But when the body becomes resistant to leptin, the brain doesn’t receive that signal properly — leading to persistent hunger, overeating, and further weight gain. This, in turn, can worsen insulin resistance, creating a vicious cycle that accelerates weight gain and metabolic dysfunction. Ghrelin also factors into the progression and symptoms of type 2 diabetes. It slows down insulin release in the pancreas, which can be beneficial for people who don’t have the condition. However, people who do have diabetes tend to have lower ghrelin levels and fewer cells that produce it.
Muscle and Bone Health
Ghrelin isn’t just about hunger; it also plays a key role in keeping your bones and muscles strong and healthy.
Leptin also affects bone and muscle health, influencing bone metabolism. Researchers have found that leptin therapy (usually through an injection) can normalize bone density in individuals with low leptin levels.
Mental Health
Hunger hormones appear to be intimately connected with mood and mental health. Abnormal cortisol levels often accompany mental disorders like depression, bipolar disorder, and psychosis. Maintaining normal cortisol secretion is important because the hormone influences neuroplasticity (the ability to form new connections, which is vital because it allows the brain to adapt to stress, experiences, and environmental changes).
Insulin also plays a major role in mental health. A 2021 study found that insulin resistance almost doubled the risk of developing depression over 9 years.
Ghrelin is also linked to mental well-being. A 2024 study found that lower ghrelin levels are associated with more severe anxiety symptoms in youth with certain types of restrictive eating disorders. Ghrelin may also have protective effects against anxiety and depression.
Brain Health
Ghrelin plays a role in learning and memory formation, and a 2019 study linked ghrelin resistance to the development and progression of Alzheimer’s disease.
Beta-amyloid, a toxic protein that builds up in the brains of people with Alzheimer’s, can block a special receptor in the hippocampus — a part of the brain important for memory — that’s normally activated by ghrelin. Researchers are looking for ways to turn on the ghrelin receptors to slow or prevent the damage that leads to cognitive decline and dementia.
CCK impacts memory and brain plasticity. It may also protect neurons from the damage caused by neurodegenerative diseases like Alzheimer’s and Parkinson’s by reducing brain inflammation and restoring mitochondrial function in neuronal cells.
Factors That Disrupt Hunger Hormones and How To Combat Them
Hunger hormones can interfere with how your body functions and various conditions and diseases can mess with your hunger hormones. So, how can you interrupt this loop and return to health?
Here are several actionable factors that can disrupt your hunger hormones and several powerful levers you can pull to get them back into balance.
Poor Sleep
When you don’t get enough good sleep, your ghrelin levels rise (making you feel hungrier), and your leptin levels drop (reducing sensations of fullness). Leptin, in particular, is influenced by circadian rhythms. When it’s in sync with your sleep patterns, you feel hungry in the morning, right before your body thinks you’ll need a boost of energy, and you feel full at bedtime, when it’s time to rest and digest.
People who are sleep-deprived have stronger cravings for high-calorie, sugary foods. If that’s you, prioritizing better sleep can help you manage hunger and cravings. (Most adults require seven to nine hours of sleep each night to recharge fully.)
Since hunger, eating, and sleep all influence each other, one way to get higher-quality sleep is to create and stick to a consistent mealtime schedule.
For more on sleep, check out our article: Sleep Hacks: How To Sleep Better With Diet And Lifestyle.
Chronic Stress and High Cortisol Levels
Cortisol, the stress hormone, increases appetite, especially for “comfort foods” high in sugar and fat. (I don’t know of many people who tend to stress-eat broccoli and kale.)
This can be a hard habit to break because these foods work, in the very short term, to reduce the experience of stress. The problem is that they further disrupt hunger hormones, which can lead to a vicious cycle of worsening food addiction.
Long-term stress, which promotes emotional eating, leads to fat accumulation. A 2024 study of Brazilian women with obesity found that the higher the participants’ stress levels (as measured by questionnaires and blood cortisol readings), the more fat they put on around the belly. This visceral fat is more dangerous to health than the subcutaneous fat that accumulates under the skin.
There are several ways to overcome stress eating. Mindful eating can combat it directly. Other techniques done throughout the day can lower cortisol levels and reduce cravings for unhealthy foods. Both meditation and breathing exercises have been shown to reduce stress and help facilitate intentional food choices.
Processed and High-Sugar Foods
Whether you’re in the grip of a craving or not, consuming refined carbohydrates (like white flour and sugars) can trigger short-term dopamine and insulin spikes that can fuel food addiction. The blood sugar ups and downs can further trigger hunger and cravings.
Ultra-processed foods (or, as Michael Pollan refers to them, “food-like products”) can do extra damage. They can disrupt the gut hormones PYY and CCK, which signal fullness when working properly. And they can also contribute to depression, which (as anyone who started “dating” ice cream after a breakup can attest) can also impact food choices.
High sugar and processed carbohydrate diets contribute to insulin resistance, which makes hunger harder to regulate. That’s because it keeps energy out of our cells, which keep signaling to the rest of the body that they’re depleted.
In short, eating a well-balanced diet of whole rather than processed foods can help maintain a healthy blood sugar balance.
Excess Body Fat
Overweight people can have high levels of leptin (which, if you recall, signals fullness) and still have the urge to eat. That’s because obesity can make the brain resistant to leptin signaling.
In other words, the body no longer recognizes fullness as a reason to stop eating, which can lead to constant hunger and overeating — even with incredibly high levels of willpower. So not only does overeating lead to putting on excess body fat, but it works in the other direction in a potentially vicious cycle: excess body fat increases hunger, which causes overeating that contributes to further weight gain.
One weight management approach that can be powerful here is to proactively choose foods that won’t pack on the pounds, even if hunger drives you to overeat them somewhat.
Try binging on fresh broccoli, cucumbers, or whole apples, and you’ll quickly realize that some foods naturally limit their intake — while still nourishing your body without excessive calories.
If you’d like to learn more, here’s an article about 11 Top Weight Loss-Friendly Foods.
Dieting and Extreme Calorie Restriction
It can be tempting to consider “heroic” measures to lose weight, like fasting for days or severely restricting calories or volume of food. While these tactics can produce results in the short term, they typically backfire hard over time.
That’s because crash diets increase ghrelin levels. Additionally, long-term calorie restriction can lower leptin, making it harder to lose weight. In other words, the less you eat, the hungrier you feel.
Your body pays much more attention to your caloric “cash flow” (what you’re taking in and spending each day) than your caloric “bank balance” (how much energy you have in fat reserves).
If you’re eating many fewer calories each day, your body is liable to go into “starvation mode.” It reasons, “Since there’s not enough food in the environment, I’d better increase hunger so that all attention is focused on finding what little there is. And while I’m at it, I’ll slow down metabolism so less food is needed to function.” A sluggish metabolism makes weight regain following a restrictive diet much more likely.
Focusing on nutrient density — getting the most micronutrients per calorie — instead of calorie counting is a more sustainable way to adjust your diet.
For more on calories and whether they matter for weight management and health, here’s an article: Should You Count Calories? How Daily Calorie Intake Fits into Health.
Sedentary Lifestyle
Not getting enough exercise may contribute to leptin resistance and reduce insulin sensitivity. While exercise can increase appetite (which makes sense since if you’re burning more calories, you generally want to consume more — like filling up your car’s fuel tank more frequently if you start driving longer distances), it also has been found to make people more sensitive to fullness signals, so they eat less overall.
A 2024 study looked at biochemical changes that occurred when men with obesity spent an hour on a stationary bicycle. Researchers found that they experienced less hunger right after working out, due at least in part to regulation of their hunger hormones.
So regular exercise, including resistance training, can be useful for weight control, cravings, and all-around health.
Dehydration
Many people mistake thirst for hunger, which can lead to overeating. (After all, the main beverage humans have evolved to drink is water, which contains zero calories and can trigger sensations of being full thanks to stretch receptors in the stomach.)
While proper hydration supports digestion and helps regulate ghrelin levels, drinking water isn’t an answer all by itself, though, especially for someone who is overweight or obese. While filling up on water can reduce sensations of hunger and bring many other benefits, it hasn’t been reliably linked to people eating less food.
Here’s an article on how to stay hydrated: Quench Your Thirst: The Science and Benefits of Proper Hydration.
Healthy Hunger Hormone-Supporting Recipes To Keep You Satiated
Eating to support healthy hunger hormone balance has never been easier — or more delicious! These recipes are designed to satisfy you with nutrient-dense ingredients that help regulate appetite, stabilize energy levels, and naturally curb cravings.
Whether starting your day with a hearty porridge, enjoying a protein-packed wrap, or sipping on a refreshing smoothie, each dish is a simple and nourishing way to fuel your body while keeping hunger in check.
1. Overnight Three-Grain Breakfast Porridge
Wake up to a warm, nourishing bowl of comfort that keeps hunger in check and energy levels steady. This wholesome Overnight Three-Grain Breakfast Porridge blends ancient grains with warming spices and naturally sweet fruit, supporting blood sugar balance and preventing those mid-morning cravings.
Packed with fiber, protein, and healthy fats, this dish helps keep leptin and ghrelin in harmony so you feel satisfied without energy crashes. Make it ahead of time for a no-fuss breakfast that fuels your day from the first bite.
2. Lentil Quinoa Collard Wraps
These protein-packed Lentil Quinoa Collard Wraps combine lentils, quinoa, and crunchy veggies in a nutrient-dense collard leaf for a meal that fuels energy and promotes fullness.
Balancing fiber, plant protein, and healthy fats helps curb stress-induced cravings. And a creamy, tangy sriracha mayo adds a flavorful kick, while pickled onions bring gut-friendly health benefits. Perfect for a light yet satisfying lunch that won’t leave you reaching for snacks.
3. The Unsweet Smoothie
Skip the sugar and fuel your body with a smoothie rich in flavor and nutrients. This energizing Unsweet Smoothie blends fruits, seeds, and leafy greens to help keep hunger hormones balanced while delivering a steady energy source.
Flax and hemp seeds provide essential fats supporting brain function and cortisol regulation, while tart cranberry juice, blueberries, and bananas create a satisfying, refreshing taste. Packed with goodness, this smoothie is a smart and delicious choice any time of day.
Take Back Control of Hunger Hormones
Modern lifestyle factors can throw your hunger system out of sync, leading to persistent hunger, cravings, weight gain, and even food addiction. Fortunately, there are things you can do to regain control over your hunger hormones.
By prioritizing nutrient-dense whole foods, managing stress, getting quality sleep, staying active, and practicing mindful eating, you can help regulate ghrelin, leptin, insulin, and other appetite-related hormones. Small, consistent changes can reduce cravings, support a healthy metabolism, and improve your relationship with food.
Featured Image: istock.com/nensuria
Tell us in the comments:
- What are your strategies for dealing with cravings?
- Which lifestyle factor adjustment could give you the biggest benefit to your hunger hormones right now?
