THE APPETITE HORMONES YOU NEED TO KNOW: WHY YOU’RE HUNGRY (EVEN WHEN YOU SHOULDN’T BE)

WHY 'EAT UNTIL YOU'RE FULL' DOESN'T ALWAYS WORK

You’ve probably heard this advice before:

"Just listen to your body and eat when you're hungry.”
”Stop when you're full."
”Everything in moderation.”

They’re popular mantras from fitness influencers to doctors to body-positive nutrition practitioners who encourage intuitive eating.

While I fully agree that our bodies are spectacular - capable of doing incredible things, even when they’re not getting their ideal fuel - this approach can overlook a critical reality: If your appetite hormones and blood biochemistry are out of balance, your intuition (AKA your body’s hunger signals) won’t be reliable.

During perimenopause, when your hormones are fluctuating wildly, intuitive eating can lead to confusion and frustration. Many women experience hunger at times they shouldn’t or crave foods that won’t support their health goals.

Something important to know is that it isn’t just a lack of willpower or discipline. Excess body fat isn’t just inert storage. It’s hormonally active and can contribute to worsening the very imbalances that make intuitive eating difficult. So while I support loving your body, part of that love means supporting it with nourishing food, movement, and the basics of health to remove some of that excess fat, because those fat stores can add to the hormonal chaos you’re already experiencing.

That’s what we’ll cover in this blog: how your hunger hormones -especially leptin and ghrelin - get out of balance, and what signs to look for when your body is sending mixed messages.

WHAT ARE LEPTIN AND GHRELIN?

To understand why you might be feeling ravenous when you shouldn’t be, we first need to introduce the two main players in appetite regulation: 

• Leptin: Known as the "satiety hormone," leptin is produced by your fat cells and signals your brain that you’ve had enough to eat. Think of leptin as the “off” switch for your appetite. When it’s working properly, you feel full and stop eating.
• Ghrelin: Often referred to as the "hunger hormone," ghrelin is produced in your stomach and sends signals to your brain when it’s time to eat. Ghrelin ramps up your appetite, so it’s the “on” switch for hunger.

But leptin and ghrelin aren’t the only hormones in charge of your appetite. There are several lesser-known hormones that contribute to the energy balance equation:

• Neuropeptide Y (NPY): Produced in the brain, NPY makes you crave carbohydrates, especially during periods of stress. Normally, leptin inhibits NPY, but chronic stress or a high-sugar diet can stimulate its release, intensifying carb cravings.
• Glucagon-like peptide 1 (GLP-1): Produced in the digestive tract, GLP-1 helps regulate blood sugar and slows digestion, which keeps you feeling fuller for longer. In conditions like obesity or type 2 diabetes, the release of GLP-1 is impaired, making it harder to stay satisfied. Some new medications (like Ozempic LINK TO MY BLOG ON OZEMPIC) on the market work by mimicking GLP-1 and upregulate it to reduce appetite and promote weight loss.
• Cholecystokinin (CCK): Found in the digestive system, CCK stimulates the gallbladder and pancreas to digest fats and proteins while also helping to reduce appetite. Unfortunately, obesity can make you less sensitive to its effects.
• Peptide YY (PYY): Produced in the small intestine, PYY reduces appetite and slows the movement of food through your digestive system. Low levels of PYY are often seen in people with obesity or type 2 diabetes, making hunger harder to control.

WHY DO LEPTIN AND GHRELIN GET MESSED UP?

When leptin and ghrelin function as they should, they help you maintain a healthy balance between hunger and fullness. But several factors can disrupt these hormones, leading to constant hunger or a lack of satisfaction after meals.

• Stress and Cortisol: Chronic stress is one of the biggest disruptors of appetite hormones. High levels of cortisol, the stress hormone, can reduce leptin's effectiveness, making it harder for your body to signal that you're full. Simultaneously, stress increases ghrelin, causing hunger even when you've just eaten.
• Poor Sleep: Lack of quality sleep doesn’t just leave you feeling exhausted - it also wreaks havoc on your hunger hormones. Studies show that poor sleep decreases leptin and increases ghrelin, leading to a never-ending hunger cycle, especially for high-calorie comfort foods.
• Dieting and Over-Restricting Calories: Extreme dieting can trick your body into thinking it’s starving. This causes a drop in leptin levels and an increase in ghrelin, making you hungrier and more prone to overeating, even when you’re trying to lose weight.
• Processed Foods: Foods high in sugar and processed ingredients can interfere with leptin’s ability to signal fullness. This condition, known as leptin resistance, makes it difficult for your brain to recognize when you’re full, leading to overeating. It’s like your appetite switch is stuck in the “on” position.

LEPTIN RESISTANCE

Leptin resistance is particularly troublesome for those with excess body fat. While we used to think of fat cells as just inert storage, research has revealed that fat is hormonally active and functions as an endocrine (hormone-producing) organ. When your fat cells produce leptin, they should signal to your brain to stop eating. But in leptin resistance, your brain becomes deaf to those signals, leaving you constantly hungry and more prone to overeating. It’s a vicious cycle: more fat leads to more leptin, but your brain can’t respond, so you keep feeling hungry even though your body has enough energy stored.

HOW PERIMENOPAUSE PLAYS A ROLE

As if all of this weren’t enough, the hormone fluctuations of perimenopause add another layer of complexity. Studies show that women in perimenopause often experience higher levels of ghrelin and lower levels of leptin, which can explain why you might feel hungrier and struggle with cravings during this time. (it’s not just in your head! You are feeling hungrier, even though you’re eating the same meals that kept you satisfied in the past!)

These shifts in leptin and ghrelin are compounded by the declining levels of estrogen and progesterone that occur in perimenopause. Estrogen and progesterone interact with your hunger hormones, meaning that as these hormones fluctuate, your hunger signals may become even more unpredictable. Many women find themselves reaching for snacks more frequently or feeling unsatisfied, even after a well-balanced meal.

This can leave you feeling frustrated and confused, especially when you haven’t changed your eating habits but suddenly find yourself gaining weight or battling constant cravings.

SIGNS YOUR HUNGER HORMONES ARE OUT OF BALANCE

If you’re wondering whether your hunger signals are out of sync, here are some common signs that leptin or ghrelin might be imbalanced:

• Constant hunger even after eating full, balanced meals
• Cravings for sugary or high-carb foods, particularly when stressed
• Feeling unsatisfied after eating, no matter how much or what you’ve eaten
• Weight gain, especially around the abdomen, without obvious changes in diet or exercise
• Emotional eating or eating as a way to deal with stress or negative emotions
• Difficulty controlling portion sizes or stopping eating once you’ve started
• Increased cravings for salty, crunchy foods, especially after poor sleep

THE FIRST STEP IS UNDERSTANDING AND AWARENESS

Leptin and ghrelin play major roles in your hunger and fullness cues, but when they’re not working properly, it can feel like your appetite is running the show. Stress, poor sleep, dieting, processed foods, and hormonal changes - especially during perimenopause - can all throw these hormones out of balance.

Understanding how leptin and ghrelin function, and what causes them to misfire, is the first step in regaining control of your appetite and managing your weight. It’s not about willpower - it’s about knowing what’s happening inside your body, and working with your body to correct the imbalance, rather than trying to push against it.

If you’re struggling with constant hunger or unexplained weight gain, your body might be sending you the wrong signals. Join my free training, "Why you’re gaining weight after 40: The 4 hormone shifts you need to know", where you’ll learn:

• The 4 hormone shifts secretly driving your weight gain after 40
• Why your go-to diet and exercise routine is failing you
• How to take back control of your weight without restrictive diets, exhausting workouts, or missing out on life.