Ghrelin is a food intake signal that is released by the stomach between meals. The signals are sent to the part of the brain known as the hypothalamus and relays them to the area of the hypothalamus known as the feeding center of the brain. When this part of the brain is activated, our body is encouraged to eat more and metabolize less. Ghrelin also stimulates our parasympathetic system, which helps promote fat storage and insulin secretion—yikes!
Out of all the hormones produced by the body after eating, like insulin or leptin for example, ghrelin is the only hormone that stimulates your body to eat more. The other hormones actually tell your body to stop eating and metabolize more so it’s easy to see why you want to keep your ghrelin levels under control!
Ghrelin Makes You Want to Eat High-Calorie Foods
During periods of fasting, ghrelin levels are increased in the body. High ghrelin stimulates the reward centers of your brain, which increases the appeal for high-calorie foods so if the fast doesn't stimulate your desire for eating enough, the increase of ghrelin increases your desire to eat even more.
A study was done to test ghrelin’s affect on high-calorie food appeal. 18 healthy 23 year old men and women fasted overnight and were fed either a 730-calorie breakfast or no breakfast at all. One group was given a ghrelin injection while the other group was given a placebo. MRI scans recorded their brain activity during the study. The study found that the group that ate a large breakfast and was given the ghrelin injection experienced an activation in the reward center of their brains, causing them to want to keep eating compared to the other group (who did not eat breakfast) and did not experience the same results.
Another study showed that a group of healthy men given ghrelin injections ate more at a free-choice buffet. They not only increased the amount of calories they ate but also scored higher than the non-ghrelin injected group on an appetite appeal test, showing that higer levels of ghrelin increased their desire for food.
Ghrelin and Fat Accumulation
Ghrelin not only increases your appetite, but also promotes fat storage, right in the mid section. Abdominal fat storage is the most dangerous type of fat to accumulate because it increases your risks of diabetes, insulin resistance and hypertension (and makes it tough to rock a bikini).
So, How Can You Suppress Ghrelin?
• Don’t skimp on protein. You don’t want to over do it but having enough quality protein can help suppress ghrelin.
• Get enough sleep. Sleep helps regulate ghrelin production.
• Have quality protein especially during breakfast. One study showed that eating lean protein in the morning can actually control hunger longer than eating at other times of the day. Great options can include eggs or a shake made with a scoop of quality protein powder mix and unsweetened coconut or almond milk, etc.
• Eat small meals at regular intervals throughout the day. Another hormone, Peptide YY, is responsible for suppressing ghrelin production. Peptide YY is secreted when you eat small meals throughout the day.
• Lower your stress. Higher stress means more ghrelin production because the body produces more ghrelin in response to anxiety.
• Add healthy-fats to your diet like avocado or salmon. Healthy-fat can curb appetite signals.
Besides your food choices, portions and habits, healthy eating and living includes so many different factors. By making slow, steady improvements to the choices you’re making each day, you’ll create a plan that continues to bring you closer to the body, health, life and lifestyle you want most.