Hunger Hormones
Organs inside the human body interact with each other with the help of chemical messengers known as hormones. There are more than 50 hormones that control a number of functions including metabolism, reproduction, growth, mood, and hunger.
In this article, we’ll discuss hunger hormones, leptin, and ghrelin.
Ghrelin – Regulates hunger by increasing appetite.
Leptin – Regulates hunger by decreasing appetite.
Leptin
Produced by adipose tissues, signals the brain to stop eating as the body has enough energy reserves. During your dieting journey you would have experienced that after a few weeks things start getting harder- weight loss slows down, performance in the gym starts to decline, cravings start to crop up, etc.
Leptin might be playing some role in this slowdown. Leptin is involved in many functions including regulating appetite, energy balance, motivation, mood, sex drive, etc. (Park et.al, 2015) (Farooq et.al, 2013). Leptin’s primary job is maintaining body composition. It signals the brain to indicate satiety levels.
i.e. More fat cells – more leptin production and vice versa.
Ghrelin
Produced by the gut, increases hunger by signaling the brain to start eating. Levels increase when fasting, and eating reduces concentrations of ghrelin.
Ghrelin levels are regulated by food intake. The level in the bloodstream is mediated by the meal timings and hunger levels. Levels of ghrelin increase when fasting. Eating reduces the concentrations of ghrelin. During a calorie restriction phase, an increase in ghrelin levels leads to increased hunger which makes dieting hard in the long run.
Leptin Resistance and increased Ghrelin production - The 2 demons
As it is produced by Fat cells, obese individuals tend to have higher levels of leptin circulating in their bodies. Constant exposure to high amounts of leptin sometimes leads to leptin resistance, reducing its appetite-suppressing effects. This creates a havoc situation inside the body, making us eat more, leading to the production of more leptin, making the body fall into a vicious cycle.
On the other hand, Ghrelin levels are also high in anorexia nervosa and increase after dieting (prolonged deficit) for the general population, which explains why it is hard to control rebound after losing weight by dieting only. This may be the body’s way of making up for weight loss by stimulating food intake and fat storage.
Conclusion
Getting an appointment with an endocrinologist to discuss health, diet, lifestyle, and genetic factors is the best thing to do if an individual feels that his hormones are not working optimally. Leptin and ghrelin both travel via the bloodstream, cross the blood-brain barrier and enter the hypothalamus. Hypothalamus is the part of the brain, which regulates hormone production and homeostasis.
Ghrelin plays an important role in the regulation of learning and memory, the sleep-wake cycle, taste sensation, reward behavior, and energy metabolism too.
When talking about the most complicated machine ever existed, no 1 hormone is responsible for 1 task, or vice versa, they work to shape our appetite and hunger. Factors such as sleep, hydration, nutrient intake, stress, activities, etc. affect these hormones and the body’s response to them.
Reference:
- Farooq, R., Ullah, S. L., & Ishaq, H. (2013). Relation of serum leptin with sex hormones of obese infertile men and women. Journal of Applied Pharmaceutical Science, 3(1), 60.
- Park, H. K., & Ahima, R. S. (2015). Physiology of leptin: energy homeostasis, neuroendocrine function, and metabolism. Metabolism, 64(1), 24-34.
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