Medical Author: Dr. Sruthi M., MBBS Medical Reviewer: Pallavi Suyog Uttekar, MD
Medically Reviewed on 3/30/2022
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What Are the 5 Hormones Involved in Hunger?
Hormones play an important role in regulating hunger and satiety.
The 5 main hormones involved in hunger include leptin, ghrelin, GLP-1, cortisol, and insulin.
Hormones play an important role in regulating hunger and satiety.
5 hunger hormones
1. Leptin
Leptin, also known as the satiety hormone, is released by the fat cells to help regulate your energy expenditure. Leptin penetrates the blood-brain barrier to communicate with the hypothalamus in the brain, which tells you whether you are hungry or full.
Because leptin is released by fat cells, increased amounts of fat cells lead to increased levels of leptin, thereby reducing hunger. However, if you are obese, you may develop leptin resistance, which interrupts these signals to the brain and causes a malfunction in the appetite-suppressing effects of leptin.
2. Ghrelin
Ghrelin, also known as the hunger hormone, has the opposite function of leptin. Ghrelin is released from the empty stomach cells to stimulate appetite as a response to hunger and starvation. The production is stopped as the stomach stretches with sufficient food.
Carbohydrate-rich foods and high sugary foods, however, do not stretch the stomach lining. This makes you eat more and increases the risk of weight gain. High-fiber and high-protein do stretch the stomach lining and therefore promote satiety.
In the long term, altered ghrelin levels affect the function of leptin. Obese people have poor signaling of ghrelin in the brain, which increases food intake and body weight.
Ghrelin-producing cells are found in the duodenum, jejunum, ileum, colon, pancreas, kidney, and placenta and found in very small mounts in the hypothalamic arcuate nucleus in the brain, an important region of appetite control.
3. Glucagon-like peptide-1 (GLP-1)
GLP-1 is produced and secreted by the intestines as food enters the body. This hormone alerts the brain that you are full and should stop eating.
Chronic inflammatory diseases or an increased intake of foods that cause flare-ups reduce the synthesis of GLP-1. This produces a negative effect on satiety signaling.
Avoiding inflammatory foods, taking probiotics, eating protein, and eating green leafy vegetables enhances GLP-1 synthesis.
4. Cortisol
Cortisol is a stress hormone produced by the adrenal glands. Stress can cause you to eat more, and researchers have found a link between elevated cortisol levels and impulsive snacking.
Dopamine, which is the happy hormone, is released when you eat. Many people crave sweet foods when they are stressed because sugar provides a temporary mood boost.
5. Insulin
Insulin is a hormone released by beta cells of the pancreas. Insulin is involved in the regulation of blood sugar levels and conversion of food energy into fat. Insulin also aids in the breakdown of lipids and proteins.
During digestion, insulin promotes the absorption of glucose by the muscle, fat, and liver cells. This glucose is either used for energy by the cells or converted into fat for long-term storage.
Excess glucose levels are caused by eating more calories than the body requires. If the cells fail to take glucose from the blood, the body will store it as fat.
What triggers imbalances in hunger hormones?
Crash diets or indiscriminate fasting
Crash dieting or improper fasting can disrupt the balance of hunger hormones in the body.
According to one study, crash diets designed for weight loss can suppress leptin hormones by 40%, which can lead to leptin resistance and increased levels of ghrelin. This eventually increases hunger and leads to more caloric intake.
When following an extreme diet, it is highly likely that you will revert to old eating habits and gain back the weight you lost—a phenomenon known as the “yo-yo effect.”
Be cautious when choosing a diet and avoid quick fix solutions or fad diets that promise rapid results. A successful weight loss strategy requires a nutritious and well-balanced diet.
Studies have shown that leptin levels fall with both a high-calorie diet and a very-low-calorie diet. The key for a healthy weight is to strike the right balance.
High stress levels
Stress has a huge impact on your body, and your eating habits can suffer as a result.
The most common cause of stress-induced overeating is elevated cortisol levels. As cortisol levels increase, leptin resistance develops. This can lead to weight gain.
Lack of sleep
When it comes to losing weight, sleep plays a huge role because it has an impact on your hunger hormones. According to studies, sleep deprivation causes hormones such as ghrelin and cortisol to increase while reducing satiety hormones. These changes increase food intake and thereby contribute to weight gain.
