What Is Ghrelin?
Ghrelin is a neuropeptide (Nervous system signaling hormone) that plays a role in short term hunger and satiety. It is secreted by special cells(ghrelinergic) that line the GI tract. It has two central fucntions: 1) It controls appetite. 2) It also controls the rate of energy expenditure. The ghrelin/growth hormone secretagogue receptor is also found in the same cells in the brain that host the leptin receptor. In a nutshell, ghrelin is released when the stomach is empty, It signals the person to eat and also gets gastric juices flowing in preparation for a meal to be ingested. When the stomach is stretched, the hypothalmus tells the cells to stop releasing ghrelin, thus the person stops eating. Ghrelin plays a central role in triggering our pleasure center in our brains (nucleus acumbens). Ghrelin exerts it affect on energy input by making people hungry; it affects energy output by controlling the amount of energy that goes to ATP(cell fuel), the amount of fat and glycogen stored, and thermogenesis(heat production). Needless to say, it plays a very strong role in out bodies built in survival mechanisms.
What are Ghrelin’s Many Functions?
Ghrelin does many functions in the body. It’s a bit like a Swiss Army Knife! It controls insulin secretion in the pancreas in response to a glucose load in the blood stream. It has a strong effect on learning and memory as well. Memory and learning are better during the day when ghrelin is higher and stomach is empty. Ghrelin acts like and “anti-depressant” due to it’s ability to cross the blood/brain barrier. Ghrelin is affected by sleep. The more you sleep, the lower the ghrelin, the lower your hunger. This ties into obesity when people sleep to little. It plays an important role in our “fear” reactions, even when adrenal hormones are absent. It also plays a role in fertility. As you can see, this hormone is complex. It is a central player in the bodies ability to regulate weight and body fat storage.
Ghrelin And Obesity
In many studies, Ghrelin has shown to have a very different response to obesity than researchers had hypothesized. It would seem to make sense that obese individuals would have an increased appetite due to ghrelin being elevated. To the contrary, obese people tend to have a low circulating level of ghrelin. So what this shows is that ghrelin secretion if down regulated in obese individuals. It could be a consequence of elevated insulin and or elevated leptin levels. Leptin and ghrelin are antogonistic to each other in their actions. Due to the down regulation in ghrelin, that causes a corresponding drop in the levels of GH released by the pituitary gland. Because GH is liptropic, it could be a large reason why obese individuals have a hard time losing weight. So how does one go about making sure ghrelin doesn’t become another hurdle in the ability to control bodyweight?
Leptin and Ghrelin will both conspire to kill weight loss efforts if given the opportunity. How do most people lose weight? The go on a calorie restrictive diet! The problem with that is if calories go too low, the body will rapidly increase ghrelin and you will have massive hunger cravings. Even the people with the strongest willpower will eventually cave in to these nonstop signals from the stomach. So its okay to cut calories, just not too much. Use a factor of 10. If your body weight is 200 lbs, eat 2000 calories per day to start. Then slowly reduce as your body weight decreases. Eat whole foods as well, especially those higher in healthy fats and fiber. This increases the satiety the body feels, thus reducing the ghrelin output. The last key is using exercise to reduce hunger and cravings. Exercise also improves hormonal profiles to aid in your weight loss efforts. Put these things into practice if you want to keep ghrelin from sabotaging your weight loss efforts.
Ghrelin: The Final Word
Weight loss/gain is a very complex process. You have a multitude of hormones that are in play when it comes to either gaining or losing weight. There are far too many players for it to be simple calories in and calories out. If I had a nickel for every time I have had this discussion, I could be retired. There is no bigger player in short term weight management than ghrelin. The best way to deal with this hormone is to intelligently manage calories, eat a whole food diet with higher fiber and good fats, and get up and exercise. If you are having a difficult time losing weight, look into Mind and Muscle T2 or Hi Tech HydroxyElite. These two products will aid you in your weight loss goals.