Leptin is a hormone made by fat tissue that is involved in appetite control. Leptin lets the brain know how much fat you are storing. When leptin levels go up, your appetite goes down. It let’s you know when you have had enough to eat. Leptin also speeds up your metabolism.
This is when everything is working well and you are lean. Most overweight and obese people actually produce too much leptin. They become what has been termed, leptin resistant.
Leptin resistance is very much the same as insulin resistance. When a person becomes leptin resistant, it takes more and more leptin to tell their brain that they are satisfied and to stop eating. Because leptin is made from fat cells, they have to make more fat to produce enough leptin to finally get the message across to the brain to stop being hungry and to stop producing fat. This creates a vicious cycle.
Foods that trigger surges in leptin production can feed into this vicious cycle. They tend to be carbohydrates such as breads, pastas, grains, cereals, and starchy vegetables. These carbohydrates can increase leptin levels for 4 to 9 hours post meal.
Another problem with leptin, as Dr. James Lavalle explains, is that it is a source of inflammatory compounds in the body such as aromatase, IL-6, TNF alpha, estrogen, cortisol, and angiotensinogen, and enzyme that contributes to hypertension.
On top of this, Dr. William Davis has said that leptin has demonstrated direct joint destructive effects. The more overweight the individual, the more leptin within the joint fluid, and the greater the severity of cartilage and joint damage.
For people to lose weight, lower inflammation, and improve their health in general, it is important for them to restore leptin sensitivity so that leptin can do its job of turning off hunger.
To restore leptin sensitivity, you can limit the amount of carbohydrates that spike leptin levels rapidly and eat more good fats, which don’t have much of an impact on leptin levels.
In the book, The Perfect Health Diet, the authors explain that leptin follows a strong circadian rhythm. Leptin levels are lower of a morning and increase over the course of the day, peaking in the middle of the night. To enhance leptin rhythm, they suggest we should eat most of our carbs around sunset.
When it comes to dieting and maintaining leptin levels, it only really matters once you are lean. If you are 40% body fat and go down to 20%, you still have plenty of leptin left in the fat cells. It is important not to confuse hunger with leptin being low. For most people, they need to diet for 3-4 weeks before starting to think about a re-feed meal. If fatter, it could be even longer.
Once you are lean, then this is where the re-feed serves its purpose in trying to avoid a decrease in leptin levels. Re-feed with clean carbs or clean fats. It is the increase in caloric intake that helps prevent the leptin from crashing.
Christian Thibadeau – Program design seminar