Table of contents:
- Main functions of ghrelin
- Ghrelin values in blood
- Relationship between ghrelin and leptin
- Foods that inhibit ghrelin
- Foods that increase ghrelin
Ghrelin is a hormone produced mainly by the stomach and intestines, which is responsible for stimulating the feeling of hunger when the stomach is empty. This means that the amount of ghrelin is increased especially during fasting, when the body realizes that it needs food. After meals, ghrelin levels decrease. In this way, ghrelin directly influences the desire to eat and appears to play an important role in controlling body weight.
Also, some studies indicate that when you are overweight, it is possible that there is an imbalance in ghrelin levels, which makes weight loss even more difficult. Having a balanced diet with foods rich in fiber and protein, for example, can be a good way to keep ghrelin levels more controlled, helping to lose weight.
Main functions of ghrelin
Ghrelin's main function is to control the feeling of hunger, helping to control weight. In addition to helping to regulate hunger, ghrelin is also important for many other functions in the body such as:
- Production of GH: a hormone responsible for growth;
- Oxytocin control: hormone involved in breast milk production;
- Heart and pancreas function;
- Natural bowel movements: helps prevent constipation;
- Release of stomach acids: which digest food;
- Sleep and mood balance;
- Strengthening the immune system;
- Sugar and fat metabolism: the way sugar and fat are used by the body.
Since ghrelin appears to have an important impact on the digestive system, the use of this hormone for the treatment of obesity has been investigated. Studies have shown that the use of drugs that block the action of ghrelin helps in controlling hunger, contributing to weight loss and preventing weight regain.
By stimulating hunger, the use of ghrelin-based vaccines has also been studied to treat very high weight loss, common in some types of cancer, and muscle loss, common in the elderly.
Ghrelin values in blood
Ghrelin levels are evaluated through a blood test, which can be ordered by a doctor or nutritionist and, for this, you must fast for 10 to 12 hours.
In people of normal weight, the average value of ghrelin is 520 to 700 pg/mL. In obese people, total blood ghrelin levels may vary depending on factors such as whether you are on a diet or not, and the time of day:
|Average ghrelin value (pg/mL)||Ghrelin value between 08:00h and 12:00h (pg/mL)||Ghrelin value after 6pm (pg/mL)|
|Obese people before starting a weight loss diet||340 to 450||up to 420||up to 480|
|Obese people after starting a weight loss diet||450 to 600||up to 575||up to 600|
In addition, adults who have had gastric bypass surgery have, on average, blood ghrelin values of up to 120 pg/mL
High blood ghrelin
Ghrelin levels are usually increased when fasting, as the body needs food and therefore produces more hormone to stimulate the feeling of hunger.This means that it is normal for ghrelin values to increase before meals, then decrease again after a person eats.
However, ghrelin levels can remain high throughout the day when there is some kind of change in eating behavior, such as in anorexia, when you are very underweight or when you lose weight quickly.
Low ghrelin in blood
In obesity, or when eating a lot of food in a short time, ghrelin levels tend to be fixed and low throughout the day. In these cases, the level of ghrelin never increases, but it also never decreases, even after meals, which makes the feeling of hunger remain constant, which can lead the person to eat more times throughout the day, facilitating the weight gain.
To maintain adequate ghrelin levels, helping with satiety and weight loss, diet and exercise are essential.For this, the help of a nutritionist or doctor in charge and a physical activity professional are important when you want a he althy, balanced weight loss, with a focus on changing eating habits and behavior. Find out the 10 reasons why you can't lose weight and what to do.
Relationship between ghrelin and leptin
Ghrelin and leptin are two hormones with different effects, which inform the brain about nutritional needs, being important for the balance between hunger and satiety, allowing weight maintenance.
While ghrelin increases the feeling of hunger, leptin does the opposite and stimulates satiety, causing you to stop eating. This means that when leptin levels increase, ghrelin levels decrease. Understand better what leptin is, why it is high and what to do.
Foods that inhibit ghrelin
Some types of food help to decrease the level of ghrelin in the blood, decreasing hunger and aiding in weight loss, such as:
- Foods rich in protein: of animal origin such as eggs, fish, chicken, milk, cheese and yogurt. Of vegetable origin such as beans, chickpeas, soy, lentils, peanuts, sesame, among others;
- Foods rich in fiber: fruits such as guava, persimmon, avocado and pear; vegetables such as kale, squash, lettuce and spinach; grains such as beans, chickpeas and peas; cereals such as brown rice, oatmeal, quinoa, whole-grain bread and pasta;
- Low-fat foods: vegetables like spinach, broccoli, arugula, kale, cabbage and others; fruits; beans and grains; sweet potato; mushrooms, garlic; white-fleshed fish such as halibut, tilapia and sea bass; skimmed milk; white cheeses (Minas cheese and buffalo mozzarella).
- Foods low in carbohydrates: vegetables such as lettuce, spinach, watercress, broccoli, cauliflower and cucumber; fruits such as strawberry, kiwi, avocado, coconut, lemon, strawberry, blackberry, blueberry; teas; and fiber-rich foods such as oatmeal, whole grain bread, and brown rice.
In addition to the nutrients present in food, the daily consumption of oligofructose supplement, a fiber present in vegetables, increases the release of hormones that give satiety and decreases the release of ghrelin, helping to control hunger.
Foods that increase ghrelin
Some foods can also cause an increase in ghrelin and, therefore, should be avoided or consumed less frequently when you want to lose weight. These are:
- Foods low in protein: sugar, teas, coffee, sweets such as cakes and cookies, industrialized sauces such as mayonnaise, ketchup, salad dressings, fruit jams and jellies, breakfast cereal, rice, pasta such as pasta and pizza.
- Foods high in sugar: glucose syrup, refined sugar, fruit juice, isotonic drinks, milk chocolate, breakfast cereals, candied and candied fruits, industrialized cookies, industrialized sauces and others;
- Foods rich in fat: full-fat cheeses (cheese, mozzarella, etc.), whole milk and yogurt, beef, margarine, ice cream, French fries, pizza, among others.
In addition to some foods, fasting also naturally stimulates up to a 2-fold increase in the release of ghrelin in the blood, causing increased hunger.