Ghrelin and Leptin: Why These Hunger Hormones Matter

Key Takeaways

• Ghrelin and leptin work together to regulate hunger, fullness, and energy levels.
• Poor sleep, stress, and irregular eating can disrupt these hormones, increasing cravings and overeating. 
• Balanced meals, consistent habits, and glucose awareness help support healthy, balanced hunger signals.

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Feeling hungry or full isn’t dependent on a conscious decision or willpower, no matter what you may have been told in the past. When and how you feel hunger and fullness are largely driven by hormones that help your body meet its energy needs. 

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Two of the most important hormones impacting your hunger are ghrelin and leptin. Ghrelin signals hunger, while leptin signals fullness; together, they help regulate your appetite, maintain energy balance, and influence long-term metabolic health. When these hormones are in sync, hunger and fullness cues feel more predictable. When they are not, cravings, overeating, and energy crashes tend to run the show.

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After this article, you’ll understand how ghrelin and leptin affect your hunger and fullness and what you can do to help support these hormones for steadier energy, stable glucose levels, and overall health. 

What Is Ghrelin? The Hunger Hormone

Ghrelin is often called the “hunger hormone,” as its main job is to tell your brain that it’s time to eat.

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Ghrelin is considered an orexigenic hormone, as it stimulates appetite. It’s produced in the stomach and released into the bloodstream when your body needs energy.¹ As it’s secreted, ghrelin activates pathways in the hypothalamus involving neuropeptide Y (NPY), which plays a role in feeding behavior, appetite regulation, and short-term energy needs. When your body needs energy, ghrelin levels rise, increasing appetite. Then, as you eat and your energy is restored, levels fall. This natural rhythm helps cue hunger and supports regular eating patterns.

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In addition to increasing hunger, ghrelin can also:^2,3

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• Increase cravings, especially during times of high stress
• Encourage food-seeking behavior
• Influence how much you eat at a meal

Certain lifestyle factors can cause ghrelin levels to spike more often or stay elevated longer than needed. These include lack of sleep, chronic stress, long gaps between meals, and very low-protein meals.^4,5  When ghrelin stays high, hunger can feel intense and harder to satisfy.

What Is Leptin? The Satiety Hormone

The hormone leptin signals fullness and regulates long-term energy balance. Leptin is secreted by adipocytes, or fat cells, in proportion to body fat stores. Once released, leptin binds to leptin receptors in the hypothalamus, where leptin signaling helps regulate how much food you eat, energy expenditure, and metabolic rate.⁶

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When your body is appropriately producing leptin, it: 

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• Reduces appetite after eating
• Support feelings of fullness
• Regulates energy use over time

For some people with obesity or insulin resistance, chronically high leptin levels may reduce leptin sensitivity, making it less effective. Known as leptin resistance, this condition makes it harder for the brain to assess energy stores and regulate food intake accurately.⁷ When leptin isn't working properly, fullness cues get harder to recognize, often leading to overeating and weight gain. 

Ghrelin, Leptin, and Glucose Regulation

Ghrelin and leptin influence overall metabolic health and energy levels by affecting insulin levels and glucose metabolism. Higher levels of ghrelin or leptin resistance can drive overeating, which can result in a larger glucose response. 

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For example, a poor night of sleep, high stress levels, or going too long between meals may increase ghrelin levels, making you feel intensely hungry and making it harder to choose a healthy, balanced meal. Combined with leptin resistance, you may not feel the urge to stop eating until you’ve eaten an excess amount of a high-energy or unbalanced meal, and experience the glucose spike and energy crash that follows. 

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However, when ghrelin levels are stable, and you experience appropriate leptin sensitivity, you feel hungry when your energy begins to dwindle, driving you to eat before your glucose levels drop too low. As you eat a balanced, nourishing meal, leptin will be secreted to let you know when you’ve had enough, supporting steady energy and a blunted glucose curve.  

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Newer evidence suggests that unbalanced ghrelin and leptin levels may also be important factors in insulin resistance, as well as in type 2 diabetes and other metabolic conditions.⁸

The Signs Your Hunger Hormones Might Be Out of Balance

From an endocrinology perspective, ghrelin and leptin are peptide hormones that help regulate food intake, energy balance, and energy homeostasis through signaling pathways in the hypothalamus. When they’re not working as they should, you may notice disruptions to your hunger, fullness, how much, and what you eat. Common signs of disrupted hunger hormones include: 

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• Feeling hungry shortly after eating. 
• Not feeling satisfied after eating meals. 
• Strong cravings, especially for sweet or high-energy foods. 
• Unexplained fatigue or noticeable glucose fluctuations
• Difficulty maintaining a consistent eating pattern

These symptoms may have other explanations, but if you’re experiencing them and are unaware of other potential causes, taking steps to support your hunger hormones may help. 

How to Support Healthy Ghrelin and Leptin Levels

Supporting healthy hormone levels helps regulate body weight, satiety, and long-term energy balance, and you don’t need a strict diet or rulebook to make a difference. Here are strategies that may have the biggest impact

Nutrition 

Hunger hormones respond strongly to patterns of eating, not strict food rules. Eating regular meals with protein, fiber, and healthy fats can support clearer hunger and fullness signals while experiencing more stable glucose patterns. 

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• Include protein at each meal⁹
• Eat fiber-rich foods like vegetables, fruits, beans, and whole grains¹⁰
• Balance your meals with protein, carbohydrates, and healthy fats to slow glucose absorption
• Eat regularly to avoid long gaps that can drive ghrelin spikes
• Avoid extreme dieting, which can disrupt hunger hormone signaling

Lifestyle

Sleep, stress, and movement strongly influence how ghrelin and leptin signal hunger and fullness. Poor sleep and chronic stress can increase hunger and cravings, while regular movement can improve leptin sensitivity and support steadier energy levels.

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• Aim for 7 to 9 hours of quality sleep per night with consistent sleep and wake times
• Incorporate simple stress management tools into your daily routine
• Prioritize regular movement, especially strength training, to increase lean muscle mass
• Keep mealtime patterns regular and consistent to avoid long periods of time without eating

How Signos Helps You Understand Hunger Signals

Monitoring your glucose with a continuous glucose monitor (CGM) helps you connect feelings of hunger to what’s actually happening in your body. With Signos, you can see how your glucose curve responds to meals, timing, and daily habits—helping you distinguish between true physiological hunger and hunger driven by stress, boredom, or routine.

Signos features that support hunger awareness:

• 24/7 Glucose Monitoring: See how dips, spikes, and rapid drops in glucose align with hunger, cravings, or energy crashes throughout the day.
• Meal and Context Logging: Log meals, snacks, sleep, stress, and activity to identify patterns that consistently trigger hunger soon after eating.
• Weekly Insights: Review trends in glucose variability, meal timing, movement, and cravings to understand which habits support steadier energy and longer satiety.
• Movement Nudges: Gentle reminders encourage light activity after higher-carbohydrate meals, helping smooth glucose curves and reduce rebound hunger.

Experiments to Try With Signos

• Protein-First Test: Eat protein and fiber before carbohydrates at one meal and compare hunger levels and glucose stability to meals where carbs come first.
• Snack Timing Experiment: Skip habitual snacks for a few days and use glucose data to determine whether hunger is tied to a true glucose drop or routine.
• Post-Meal Movement Trial: Add 10–15 minutes of walking after meals and observe whether glucose stays steadier and hunger returns more gradually.
• Sleep vs. Hunger Check: Compare hunger signals after well-rested nights versus short-sleep nights to see how sleep quality affects glucose swings and cravings.

Over time, these insights help you build intuition about hunger, using real data to eat in response to your body’s needs rather than relying on habits or guesswork.

The Bottom Line

Ghrelin and leptin are two hormones that play a big role in hunger, fullness, body weight, and blood sugar stability. Regular balanced meals prioritizing protein and fiber, a consistent sleep schedule, stress management, and regular exercise can all help you support balanced hormone levels. Signos and continuous glucose monitoring can help you understand how your glucose levels, lifestyle, and eating habits affect your hunger and fullness signals, energy, and metabolic health. 

Learn More With Signos’ Expert Advice

If you want to understand better how your daily habits influence your metabolic health, Signos offers expert-backed education and tools to help you build healthier routines. You can explore how glucose patterns connect to energy, hunger, and your overall well-being, and learn more about glucose levels through Signos’ blog.