Why Are You Always Hungry Even After Meals?

One of the hungriest animals on the planet has been called “the tiny terror.”

It's known as the American Pygmy Shrew. It weighs about as much as a dime, has a heart rate over 1,000 beats per minute, and it's metabolism is so high it eats 3x it's bodyweight each day. In fact, it requires so much food that it can only sleep for a few minutes each day.

Luckily, we don’t have to worry about consuming three times our bodyweight each day, but some of us feel like the American Pygmy Shrew because we’re hungry all the time – even after meals.

So why is it that some people are always hungry?

Let's focus on Three Hunger Factors that can fly beneath the radar and crank up your appetite – without you even knowing it.

Why Are You Always Hungry?
​3 Hunger Factors

Hunger Factor #1: Lack of Sleep
Lack of sleep influences hunger in three ways.

First, it impacts the hunger hormones ghrelin and leptin.
Your stomach releases ghrelin which stimulates your appetite. Your fat cells release leptin which increases fullness (decreases your appetite). When you don’t get enough sleep, ghrelin levels spike and leptin levels drop. That means, the next day you feel hungrier and it becomes harder to feel full.

Second, it activates the endocannabinoid system.
Lack of sleep increases hunger the same way marijuana does because it impacts the same areas of the brain. According to Dr. Erin Hanlon of University of Chicago, “Sleep restriction seems to augment the endocannabinoid system, the same system targeted by the active ingredient of marijuana, to enhance the desire for food intake.”

In fact, sleep deprivation boosted endocannabinoid levels by 33%. This makes your drive for certain snacks stronger and it becomes harder to resist them as well. A study published in the journal Sleep found that sleep-deprived subjects consumed more snacks and pick foods with 50% more calories and twice the fat, compared to when well-rested.

Third, your brain becomes more responsive to junk food.
Scientists at University of California Berkeley looked at the brains (using fMRI scans) of sleep deprived subjects when exposed to certain foods. Sleep deprived subjects’ reward centers of the brain lit up more when shown high-calorie foods, compared to well-rested subjects. In addition, the sleep deprived subjects had less activity in the part of the brain that controls behavior. This meant they were less likely to resist junk food urges.  

These three combined cause a perfect storm, making you crave more food and lower your self-control.

Hunger Factor #2: Lack of Protein.
Another factor in fullness is protein.

One reason is that protein (just like sleep) impacts hunger hormones. Protein decreases ghrelin levels and increases a hormone called peptide YY which increases fullness. This means you have less of an appetite and you feel full quicker.

A 2011 study published in the journal Obesity found that when overweight men consumed 25% of their diet as protein, their urge for late-night snacking dropped by 50%. Plus, they felt fuller and thought about food less often.

Dr. Wayne Campbell of Purdue has found in his studies, "We have also shown that when diets are inadequate in the amount of protein and don't meet national recommendations, desire to eat increases."

Another reason is phenylalanine. Phenylalanine is a chemical produced when the body breaks down high-protein foods such as eggs, beef, and fish. This chemical releases leptin and GLP-1, which both increase your fullness.

According to Dr. Richard D. Mattes who published a recent study in Journal of Academy of Nutrition and Dietetics: “A good deal of evidence suggests that protein activates satiety hormone release and so should be most strongly tied with fullness ratings.”

So increasing the amount of protein you eat during your meals can help you feel full longer. Plus, this can lead to consuming fewer calories the rest of the day. One 2005 study in the American Journal of Clinical Nutrition found that when overweight women increased their protein intake from 15-30% (of total calories), they felt more satisfied and consumed 441 less calories each day.

And it’s not just protein consumed during the meal.

Protein in the morning appears to affect hunger later in the day. In a 2018 study published in Journal of Dairy Science, subjects who consumed a higher-protein breakfast had lower appetites the rest of the day. Another 2007 study by researchers at Pennington Biomedical Research Center had dieters eat a bagel or two eggs for breakfast (5x per week) for eight weeks.

According to researcher Dr. Bikhil V. Dhurandhar, "When people eat eggs, rich in protein, at breakfast, they felt more satisfied and consumed fewer calories throughout the day, compared to those who ate a primarily carbohydrate meal like a bagel." Plus, compared to the bagel group, the egg group dropped their waist circumference by 83%, lost 65% more weight, and had increased energy levels.

Speaking of bagels…

Hunger Factor #3: Too Many Refined Carbs.
Refined carbs are just about everywhere.

They could be pasta, bread, desserts, baked goods, chips, candy, snacks, etc. Usually they are made with white flour or are heavily processed. The problem with refined carbs is that they have been stripped of most of their vitamins, minerals and fiber.

Why do refined carbs increase your hunger?

Without fiber, your body digests these carbs extremely quickly. These are known as high-glycemic foods.  They temporarily spike your blood sugar levels, which gives you a jolt of energy. But shortly after your blood sugar tends to drop, which signals the brain that it’s time to eat again. Think about a basket of bread at a restaurant. This is a perfect way to rev up your hunger. The bread digests quickly, spikes your blood sugar, and then your appetite soars.

High-glycemic foods also mess with your brain. Studies from the Journal of Neuroscience have found that these high-glycemic foods activate the primary pleasure and reward center in the brain (the nucleus accumbens). Sugar especially has an unusual impact on the brain.

Usually, your brain’s insula, hypothalamus, and thalamus (which motivate you to eat) tend to “quiet down” after a meal. But when you eat sugar specifically (even honey) it keeps those parts of the brain lit up, motivating you to want to eat more. This tricks your mind into thinking you’re still hungry. According to Dr. Robert Lustig, a pediatric endocrinologist at University of California, “Your brain tells your body you’re not full, and you have the urge to eat more to feel satisfied.”

High-glycemic foods also activate addiction centers of the brain.
One of the most revealing effects came from a study done by Dr. Ludwig, where obese men drank either a high-glycemic or low-glycemic milkshake. Both milkshakes tasted identical. Naturally, subjects who drank the high-glycemic milkshake had a spike in blood sugar. But it was four hours later where things got interesting… 

Four hours after drinking the high-glycemic milkshake, subjects’ blood sugar had dropped and they were hungrier. Plus, when looking at their brains, they found the parts responsible for addiction and cravings were highly activated. Despite being a small study, every single subject had the same response when they drank the high-glycemic milkshake.

Okay, let’s go through a quick summary.

We talked about three hunger factors.

Hunger Factor #1: Lack of Sleep.
When you don’t sleep enough, leptin levels drop and ghrelin increases. Meaning: the next day you are hungrier and it’s harder to feel full. Lack of sleep also increases hunger the same way marijuana does by activating the endocannabinoid system. Sleep-deprived subjects ate more snacks and ate foods with 50% more calories and twice the fat, compared to when they were well-rested. And sleep deprivation decreased activity in the areas of the brain responsible for controlling behavior. This made it harder to resist urges.

Hunger Factor #2: Lack of Protein
Protein decreases ghrelin levels and increases a hormone called peptide YY which increases fullness. This means you have less of an appetite and you feel full quicker. When the body breaks down high-protein foods it releases phenylalanine, which then releases leptin and GLP-1. These two increase your fullness. Plus, it’s not just protein during a meal that affects appetite. Studies show that consuming a higher-protein breakfast lowers appetite the rest of the day. (Note: Here's one of my favorite breakfasts/ desserts for keeping you full for hours.) 

Hunger Factor #3: Too Many Refined Carbs
Your body digests refined carbs very quickly, which spikes your blood sugar levels and signals the brain that its time to eat again. They also activate the primary pleasure and reward center in the brain. Sugar in particular keeps certain parts of the brain lit up, motivating you to want to eat more. When subjects drank high-glycemic milkshakes, they were hungrier and addiction centers of the brain were highly activated.

So take an honest look at each of these.

Determine which one may be the culprit for you. And then I challenge you to act on one of them. Then take one week… or even two weeks to experiment. Focus on getting a full night’s sleep… eating protein with each meal… or removing refined carbs… and see how it affects your hunger levels. That way you won’t feel as hungry as an American Pygmy shrew.  ​