Ghrelin is a hormone mainly produced in the stomach when it is empty. It is also produced in the small intestine, brain, and pancreas.
Ghrelin travels through the bloodstream to the brain, where it acts on the hypothalamus. The hypothalamus is a part of the brain, which produces hormones that regulate hunger, mood, thirst, and many other important functions within the body.
Ghrelin is often referred to as the hunger hormone because its primary role is to regulate appetite. When ghrelin activates its receptor — growth hormone secretagogue receptor — it
In people who are trying to lose weight or who have recently lost weight, ghrelin levels are often higher, making it challenging to maintain weight loss.
For example, one
Ghrelin can also signal the body to decrease brown fat thermogenesis. When this happens, the body burns less fat at rest. Brown fat is known for its
Studies show that ghrelin also affects a person’s sleep/wake cycle, taste sensation, and reward-seeking behavior.
As it plays a role in reward processing, many
It can also stimulate gastric acid secretion and
Levels of ghrelin frequently change throughout the day and are primarily controlled by food intake.
However, research remains conflicted on this point. Yet a 2015 review suggests that ghrelin levels are low in people with obesity and even lower in people with obesity who also have a binge-eating disorder.
Interestingly, experts believe people who have undergone weight loss surgery have lower levels of ghrelin, which may make it easier to keep weight off.
In particular, one recent
People with certain health conditions also tend to have elevated ghrelin levels.
People with obesity and Prader-Willi syndrome (PWS) have very high levels of ghrelin circulating, which may play a role in their constant sense of hunger and difficulty controlling weight.
Additionally, people with Hashimoto’s thyroiditis, anorexia nervosa, bulimia, and cachexia from illness tend to have higher hunger hormone levels.
Ghrelin levels also may be higher during periods of stress. Higher ghrelin levels are thought to have an
Although elevated ghrelin levels are commonly perceived as unfavorable and associated with increased appetite, certain individuals may benefit from higher ghrelin levels.
For instance, someone struggling to gain weight or with wasting syndrome may benefit from the appetite-stimulating effects of ghrelin.
Newer studies suggest ghrelin administration may potentially be helpful in patients with cancer cachexia because it can help reverse weight loss and protein breakdown in catabolic states. Although short-term ghrelin administration appears to be safe and well-tolerated, we need more studies on its effectiveness and safety before recommending it.
Animal research on how cannabis increases appetite by stimulating ghrelin production also appears to be promising to support its use in treating illness-induced anorexia.
Ghrelin levels may
However, it is important to note that other
A person who wants to naturally decrease ghrelin levels may want to try some of the following interventions.
Follow a healthy diet
People’s ghrelin levels tend to increase when on a diet and not eating enough calories. Avoiding an empty stomach and eating a nutrient-rich diet may help limit ghrelin secretion.
According to the
- vegetables of all types
- fruits, especially whole fruit
- grains, at least which half are whole grains
- low fat dairy
- lean protein
- oils, such as olive oil and those naturally occurring in nuts and fatty fish
Some foods may also decrease ghrelin levels. In one older
Get adequate sleep
Poor sleep patterns are tied to
Eat more protein
Consuming high protein meals and snacks can help promote satiety and reduce ghrelin levels. In fact, many meal-related studies have shown significant reductions in hunger and increased fullness following high protein meals.
Although removing stress altogether is near impossible, studies show that
Some animal studies suggest it may reduce anxiety and have antidepressant-like properties, while other studies suggest it may promote these behaviors.
Regular physical activity, adequate sleep, and practicing yoga or meditation can help minimize stress.
Research surrounding the effect of exercise on ghrelin levels remains conflicting. In one
The exact mechanism behind these effects remains unclear, but researchers believe it is likely due to elevated blood flow redistribution and weight loss from exercise.
Ghrelin is known as the hunger hormone due to its key role in appetite regulation. High levels of ghrelin lead to an increase in appetite and food intake. However, the body needs ghrelin because it is involved in many processes. These include improving heart health, influencing bone metabolism, and preventing muscle breakdown.
A person who wishes to naturally reduce ghrelin levels in the body may consider eating a healthy, fiber-rich diet, consuming adequate protein, exercising, getting enough sleep, and minimizing stress.
In contrast, someone with illness-induced anorexia or difficulty gaining weight may benefit from higher ghrelin levels to promote hunger and weight gain.