Trying hard to reduce weight, but can’t curb your hunger? It is all part of the work of Ghrelin, or better known as the hunger hormone. Research shows that a large percentage of people who reduce weight by undergoing a diet can regain weight in just one year. This is partially due to our body’s appetite and weight regulating hormones. Research also shows that there is an elevated serum ghrelin level in female subjects relative to male ones. So is Ghrelin a bad guy? Let’s find out. This article is going to give you complete insights into what is Ghrelin and how to control your hunger. 

What is the hunger hormone of ghrelin?

Ghrelin is your hunger-causing hormone and is produced or released in the stomach when it becomes empty. It basically tells your brain that you are hungry and to seek out food. The emptier your stomach, the more ghrelin hormone is produced and hence more hunger. In other words, food intake definitely influences your ghrelin levels.

When do our hunger increase and decrease?

The hunger which is influenced by the ghrelin hormone increases before a meal and then reduces after the meal. It also increases at night and then reduces in the morning after breakfast. This could also be a reason behind night snacking tendencies.   

What are the functions of ghrelin?

Ghrelin is known as the hunger hormone as it stimulates appetite, increases food intake, and promotes fat storage. It also stimulates the release of growth hormone from the pituitary gland, which, unlike ghrelin itself, breaks down fat tissue and causes the build-up of muscle. Ghrelin also plays an important role in the control of insulin release and has protective effects on the cardiovascular system.

chart showing the control of food intake

What are the advantages of the ghrelin hormone?

Having a controlled level of the Ghrelin hormone can have many advantages

  • Regulates Inflammation
    Ghrelin is known to be a potent anti-inflammatory mediator and can provide therapeutic treatment for inflammatory diseases and injuries. Ghrelin is needed for immune tolerance. It increases the anti-inflammatory cytokine IL-10. Ghrelin also reduces cell death and increases cell production
  • Help Fight Autoimmune Diseases
    Ghrelin can help patients with rheumatoid arthritis, ulcerative colitis, multiple sclerosis, Parkinson’s disease, Crohn’s disease, cardiovascular disease, and inflammation from brain injury. It protects the lungs, liver, kidneys, and other organs from toxic by-products of oxygen reactions and inflammation injury. It also protects the heart from inflammation injury and improves heart function.
  • Enhances Learning and Memory
    Ghrelin can enter the long-term memory storage part of the brain through the blood. Studies done on rats by injecting them with Ghrelin showed an increase in learning and brain function. Apart from this, it also enhances neuronal firing by activating the NMDA receptor
  • Influences the Growth Hormone
    Ghrelin influences the release of growth hormone by activating the growth hormone secretagogue receptor (GHSR) which thereby increases growth hormone release.
  • Enhances Dopamine Release
    Ghrelin also amplifies dopamine action and enhances dopamine release in the hypothalamus, amygdala, and nucleus accumbens (pleasure center). This dopamine release and amplification can increase physical activity and motivation.
  • Induces Bone Formation
    Ghrelin induces bone-promoting cells and increases bone mineral density. In women, blood ghrelin level has a positive correlation with bone mineral density during peri-, post-, and perimenopause.

What are the defects of the ghrelin hormone?

Having too much of the Ghrelin hormone could induce many serious consequences 

  • Anxiety and Stress
    When your ghrelin hormones are too high, you will feel the extreme hunger and dissatisfaction of not feeling enough of eating. This can induce a stressful situation by increasing the cortisol levels. Study finds that ghrelin, produced during stressful situations, primes the brain for post-traumatic stress disorder(PTSD) as well.
  • Obesity and Weight Gain
    With the increase in hunger, comes the increase in food intake. Eating more than what the body burns causes extra fat storage and waste calories which leads to weight gain and maybe even obesity over time. 
  • Lack of Energy
    Along with energy intake, ghrelin also affects energy expenditure. Studies show that the increase in ghrelin regulates the energy according to the food intake. Overeating can cause the energy expenditure to also heighten thereby causing a lack of energy.
  • Affects Fertility
    Studies show that ghrelin has been reported to inhibit early embryo development. Other studies show that it can influence the reproductive system by regulating hormone secretion from the brain and by acting directly on the gonads to affect tissue development and steroidogenesis.
  • May Promote Cancer Cells
    Recent studies have found that too much of the ghrelin hormone can induce colon cancer cell proliferation. Furthermore, ghrelin also promoted oral cancer proliferation.
  • Risk-Taking Tendencies
    A ghrelin spike induces an extreme hunger situation which subconsciously drives us towards eating more and unhealthy food to quench the hunger. It also makes the mind decisions unclear as it directly influences the hypothalamus of the brain,  thereby making rash decisions.

two women measuring their hips with a measuring tape

What happens if you have too much ghrelin hormone

High levels of the Ghrelin hormone can cause severe obesity, extreme hunger, and learning difficulties which are widely known as a disease called Prader-Willi syndrome. Ghrelin hormone is also known to increase when dieting, which is why it is so hard to stick to a strict diet plan. High Ghrelin is not a cause of obesity though, as studies proved that ghrelin levels are usually lower in people with higher body weight compared with lean people. Although there is a suggestion that obese people are actually more sensitive to the hormone. Ghrelin levels are also high in cachexia and the eating disorder, anorexia nervosa. 

 

What happens if you have too little ghrelin hormone

If you have a Ghrelin deficiency, you would not feel hungry at all and hence there will be an absence of appetite. This could lead to possible eating disorders, being underweight, and other health issues. The absence of appetite could also lead to not having enough vitamins and nutrients that the body requires on a daily basis. Hence you would be prone to all kinds of physical and mental health issues. 

How to take control of your hunger hormone?

Optimizing your Ghrelin level is a crucial step in controlling your hunger thereby keeping you fit and healthy. Below are a few points that can help you Optimise/decrease/control your hunger hormone.   

  • Regular Exercise
    Regular physical activity improves overall hormonal balance, weight, and a sense of wellness. A study also shows that exercise can burn the extra calories brought by ghrelin thereby keeping the body from being obese. 
  • Maintain a Good Diet
    A good diet should include all the essential macronutrients and micronutrients. Ghrelin levels will begin to increase about 3 hours after eating. Eating at the right times will keep your ghrelin and leptin hormone levels stable. Crash diets and calorie restrictions can increase the ghrelin hormone leading to bad food choices and cravings. 
  • Eat more Protein
    Protein can slow gastric emptying and provide satiety. It can also boost metabolism and reduce appetite. Studies show that protein is by far the most filling food resource and can reduce the ghrelin levels in your body. Apart from this, protein intake also improves muscle building and repair. 
  • Managing Stress
    Stress is caused by the cortisol hormone and can cause overeating, alcohol consumption, poor food choices, more sugar consumption, and overthinking, all of which can alter our sleep patterns. A study in 2016 showed that poor management of stress can adversely affect the ghrelin hormone thereby affecting our mood which brings out all the previously mentioned symptoms. Increased ghrelin levels are just a natural process of the body to cope up with the depression the mind is going through as per the study. Hence managing stress is a very key factor that affects the ghrelin hormone.  
  • Getting Enough Sleep
    Most people require about 7-9 hours of sleep. A study in 2004 showed that people with fewer than 7.7hrs of sleep had more elevated ghrelin levels, which also led to increased appetite and increased BMI (body mass index). Getting enough sleep also gives your body enough relaxation, thereby providing you with more energy to do the day’s work. If this natural energy is down, our body subconsciously seeks the need for energy from food.    

Chart showing the hours of sleep required according to age

What is the female fat-burning hormone?

The Female fat-burning hormone is called Leptin. Leptin is a hormone produced by the body’s fat cells, also known as the starvation hormone. Leptin’s main action is long-term regulation of energy, including the number of calories you eat and expend, as well as how much fat you store in your body. Leptin is the hormone that controls when and how much you eat. Eating causes your body fat to go up, causing your leptin levels to go up. Hence you eat less and burn more. Also, when you don’t eat, your body fat goes down, causing your leptin levels to dropdown. At that point, you eat more and burn less.

Leptin vs ghrelin hormones

Ghrelin hunger hormone v/s leptin starvation hormone - Graph

Leptin is the satiety hormone. Ghrelin is the hunger hormone. When ghrelin levels are high, we feel hungry, after eating, ghrelin levels fall, and we feel satisfied. 

Ghrelin and sleep 

A study done by the sleep foundation shows that there is an important relationship between sleep and nutrition. A major part of that relationship is the link between sleep and overeating. It also shows that insufficient sleep increases overeating and unhealthy food choices. A lack of sleep has been found to trigger increased levels of ghrelin and decreased levels of leptin, leading to increased hunger and appetite. This makes overeating more likely, especially since more time awake creates increased opportunities to eat 

So is ghrelin a bad hormone?

From this whole article, you would have realized that there are many advantages and defects of the Ghrelin hormone, even if they are too high or too low. Keeping it optimized and controlled will provide us with the best results. Hence it is vital to stay on track with a proper diet plan, good sleep, and good habits.

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Reference

PubMed(2007) – Weight regain in U.S. adults who experienced substantial weight loss, 1999-2002 – https://pubmed.ncbi.nlm.nih.gov/17572309/ 

You and your hormones(2018)  – Ghrelin – https://www.yourhormones.info/hormones/ghrelin/ 

Center spring MD – 5 Ways to Control Your Hunger Hormone with Functional Medicine – https://centrespringmd.com/5-ways-control-hunger-hormone/ 

Healthline – Kris Gunnars (2018) – Leptin and Leptin Resistance: Everything You Need to Know – https://www.healthline.com/nutrition/leptin-101#:~:text=Meet%20Leptin%20%E2%80%94%20A%20Hormone%20That%20Regulates%20Body%20Weight&text=Leptin’s%20primary%20target%20is%20in,a%20normal%20rate%20(4)