Health 

Ghrelin and Leptin: Understanding Your Hunger Hormones

March 11, 2021 6 min read

Person cutting a pancake on a plate for breakfast

For decades, dieters have scoured the bookshelves and medicine aisles in search of a holy grail for weight loss. And while there’s still no easy fix to dropping pounds, nutrition scientists are closer to solving the puzzle of weight and hunger. Chief in their understanding are the hormones ghrelin and leptin, which play a role in both appetite in weight loss. 

A hormone manufactured by fat cells, leptin plays a fundamental part in curbing appetite. However, not all individuals have the same levels of this appetite-suppressing hormone in their blood. Not only do people who are obese typically have higher levels of leptin, but they also tend to build resistance to its ability to suppress hunger. As a result, they may be more prone to overeating. On the contrary, more slender people tend to have reduced leptin levels in the body and lower resistance.

Another critical hormone, ghrelin, is known for its ability to increase appetite by sending the brain hunger signals. Logically, individuals who experience more intense and frequent hunger pangs are more vulnerable to overeating and gaining weight than those who don’t. Thus, both leptin and ghrelin can affect one’s ability to regulate weight successfully. 

While losing weight is no easy feat, there are steps you can take to drop pounds and improve your overall health. Keep reading to learn more about ghrelin and leptin and find out how you can start optimizing these hormone levels in your body. 

Understanding ghrelin

Widely known as the appetite-increaser, ghrelin originates in the stomach before sending hunger signals to the brain. People who are obese tend to have lower ghrelin levels, while underweight individuals or those struggling with an eating disorder experience higher levels.

Moreover, experts believe that those who are obese may also be more sensitive to ghrelin than those on the slender side. According to recent studies, obese individuals may have an overactive ghrelin receptor, or GHS-R, causing them to suffer more hunger pangs and take in more calories.

Ghrelin may also affect how quickly you start to feel hungry after eating. Typically, ghrelin levels increase when you’re fasting and right before a meal. Conversely, ghrelin levels drop for around three hours after a meal. 

It’s worth noting that dieting can actually cause ghrelin levels to increase. The result is that dieters may feel more hungry and struggle to achieve weight loss.

Understanding leptin

While ghrelin is known to increase hunger levels, leptin has the opposite effect. This appetite-suppressing hormone comes from fat cells and tells the brain when the body has a sufficient supply of stored fat, with higher levels correlating with more body fat. 

However, in obese individuals, the brain may not respond appropriately to leptin’s signals. As a result, people may keep eating when they’re full. Additionally, leptin levels can vary based on when an individual last ate and how much sleep they’re getting.

Leptin is supposed to signal the brain to stop eating. However, if the brain doesn’t get this hormonal signal, it may assume that the body is starving and take steps to hold onto more fat. As a result, those who aren’t receptive to leptin end up eating more than necessary. Additionally, the brain may instruct you to expend less energy to conserve calories. In the long run, this hormonal defect can lead to increased weight gain. 

Couple eating pasta and salad together

Optimizing hormone levels in the body

Ignoring the signals these hunger hormones are sending to the body is often challenging, if not impossible. However, there are some steps individuals can take to alter ghrelin and leptin levels and potentially curb their appetites. 

Nutrition scientists believe the foods you eat have a significant impact on hunger levels. For example, consuming foods high in fat can hinder the body from sending out signals that you’ve had enough. 

On the other hand, eating foods rich in protein and whole grains can suppress ghrelin levels and curb appetites. Keep reading to learn how you can optimize your hormone levels and control weight and hunger. 

Correcting leptin levels

If your leptin levels are too low or too high, you may be able to take steps to correct the imbalance. Because leptin tends to drop when individuals drop pounds, maintaining weight loss can be a challenge. 

Fortunately, you can boost leptin sensitivity by avoiding sugar and other substances known to cause inflammation. Instead, opt for anti-inflammatory foods such as fatty fish. According to a study involving dieting women, those who consumed fish oil and alpha-lipoic acid lost more weight and enjoyed a lower drop in leptin than those who didn’t take the supplements. 

Reducing lipid levels may also be important in the fight to optimize leptin levels. If you have high triglycerides, your body may be less capable of transporting leptin from your blood to your brain. Trading out refined carbs for protein and fiber can help get triglycerides in check, thereby improving leptin sensitivity and boosting overall health.

Additionally, exercising can increase sensitivity to leptin. According to one study from the University of Oslo involving 186 men with metabolic syndrome, decreasing food and increasing exercise resulted in reduced plasma leptin concentrations and body mass index.

Correcting ghrelin levels

Individuals looking to lose weight may also see positive results when they optimize their ghrelin levels. While ghrelin levels tend to drop after eating, studies show they only fall slightly in overweight and obese people. As a result, the body doesn’t send as strong of a signal to the hypothalamus telling you to stop eating.

The good news is there are steps you can take to correct your ghrelin levels. Avoiding sugary drinks and high-fructose corn syrup are excellent ways to ensure ghrelin levels rise after a meal. Additionally, those looking to cut weight should strive to eat protein at every meal, including breakfast. Doing this can affect ghrelin levels and appetite for the rest of the day. 

 Pecans on a cutting board to add to muesli for breakfast

The connection between sleep and weight loss

It’s not just the foods you ingest that impact your weight and appetite. Anecdotal evidence suggests that Americans’ sleep problems have increased along with their body mass index (BMI) in recent years. In other words, U.S. adults are sleeping less and gaining more weight. The result is an uptick in chronic health conditions and metabolic disorders associated with obesity.

Studies show there’s a significant connection between sleep and hunger hormones. In fact, one study involving male participants showed that going without sleep increased both hunger and ghrelin levels. Study participants who slept 10 hours did not suffer these negative consequences. 

It’s not just long-term sleep disturbances that lead to overeating. According to studies, getting only four hours of sleep for just two nights in a row was enough to drop circulating leptin levels and increase ghrelin levels. These individuals also self-reported more hunger than those who slept the appropriate amount. 

On the other hand, research indicates that getting a full night’s sleep allows the body to regulate hunger hormones accurately, thereby controlling appetite and preventing people from overeating. 

In summary

Many of us are looking for ways to lose weight and improve overall health. However, the simple truth is that dropping pounds is much harder for some people than it is for others. While having the willpower to choose healthy foods and hit the gym is part of the battle, hormone levels can also play a role in whether someone has an easy or a difficult time shedding weight.

According to nutritional scientists, two hormones known as ghrelin and leptin profoundly affect how the body experiences hunger. Produced in the body’s fat cells, leptin releases signals to decrease hunger pangs. In individuals within a healthy weight range, leptin tells them when to stop eating. However, individuals who are overweight tend to build leptin resistance. As a result, they may have trouble knowing when they’re hungry and when they’re full.

Like leptin, ghrelin affects appetite levels by sending hunger signals to the brain. Along with increasing hunger, ghrelin boosts food intake and promotes fat storage. In people of a healthy weight range, ghrelin levels tend to fall after a meal. However, the drop is much lower in those who are overweight or obese. 

The good news is there are ways to optimize your hunger hormones and get fit. One of the best ways to control leptin and ghrelin levels is to alter your diet to include more healthful foods. Along with reducing sugar and fat levels, aim to consume more protein, whole grains, and fiber

Additionally, getting more exercise and sleeping at least eight hours a night can go a long way toward controlling your hunger hormones. By getting your levels of leptin and ghrelin in check, you’ll be one step closer to losing weight and achieving your health and wellness goals. 

April Maguire - Contributing Writer, Physician’s Choice