Leptin was discovered more than twenty years ago (in 1994) and one of the main hormones responsible for appetite control and appetite suppresion. In a way, Leptin reports your nutritional status to your brain and directly manipulates the feel of hunger.
What is Leptin ?
Leptin is a hormone created by the fat (adipose) cells and the enterocytes in the intestine. Like we mentioned, leptin regulates hunger by supressing it, which in turn decreases fat storage in adipocytes.
How does Leptin work ?
Leptin’s primary target are the receptors in the area in your brain called the hypothalamus. The hypothalamus is a small region located at the base of the brain, near the pituitary gland. It plays a very important role in many biological processes such as temperature control, hunger control, hormone production control etc.
What Leptin does is, it signals the brain that a person has enough energy stored inside their fat cells to engage normal metabolic processes. When your leptin levels pass a certain point, the brain is signalized that you have enough energy stored to function normally : do physical and intellectual activities normally, eat, sleep, burn energy normally, grow etc.
The Leptin levels produced in our bodies are controlled by two factors:
– Leptin is secreted by the fat cells in the body like we mentioned, predominantly by the fat cells in the small intestine, so obviously the level of body fat a person carries plays a vital role in secreting the hormone. In theory, the higher the body fat percentage a person carries, the higher the leptin levels in your body.
– The second factor of blood leptin levels is your calorie intake. Lower your calorie intake for long enough and leptin levels will drop, regardless of the body fat percentage you carry.
So this is what basically happens when you lower your calories:
First your leptin levels start dropping (from research it has been shown that they can drop by around 50% within just one week of low calorie consumption), which is followed by your brain getting a signal that you are not getting enough calories. This is when your body goes into starvation mode.
Your brain then slows down the metabolism and creates a hormonal environment that is very suitable for FAT GAIN. Cortisol levels increase and thyroid levels decrease. This is a normal process as the brain tries to protect the body from degrading.
This is when hunger also kicks in and before you know it, you just created a fat storing environment, instead of a fat burning one.
It would be really amazing if a person could keep the Leptin levels high and stable while at the same time they eat low calories for prolonged periods. This way they could have an ideal hormonal environment for building muscle and losing fat.
So what is the solution to this problem ? How can you consume low calories while still maintain high Leptin levels ?
As we already said, leptin levels decrease by about 50% after only five to seven days of dieting. While this change happens relatively gradually, the opposite change happens quite exponentially. After a substantial increase in caloric intake, leptin levels shoot back up rapidly.
According to some research results, it only takes 12 to 24 hours for Leptin levels to climb back up after you have increased the amount of calories you consume.
This effect is even greater when you consume large amounts of carbohydrates. Research shows that when only fats and protein are consumed, they have very little effect on leptin, but when a larger amount of carbs in introduced with your meals, this hunger-suppresing hormone skyrockets back up.
It’s obvious that the answer to the low leptin levels is a high calorie, high carbohydrates cheat meal once every 7-8 days while you are dieting. So if you have dropped the calories in order to lose fat, try adding a high calorie meal once a week to restore your leptin levels.
This could be the answer why protocols such as intermittent fasting produce good results over time.
Of course, when it comes to fat loss there a number of other factors and hormones involved, so the matter is not just back and white. These are the 4 Main Hormones Responsible for Controlling Your Weight and How You Can Fix Them