Leptin was discovered in 1994 by Friedman and associates. Leptin is the first to be discovered in the group called adipocytokines. The word is derived from Greek; adipo means fat, cyto means cell and kinos means movement. Leptin is a protein circulating in blood and intimates the brain how much of energy the body has in store as fat cells. Higher the fat in the body greater is the Leptin in circulation. When, in the early days of human history, in a famine the body used up the fat to meet the daily energy requirements. Leptin levels falls to increase food intake and reduces metabolism to get the level back to normal. There is no upper limit cut off for Leptin and hence it keeps on increasing.
A chronic high level induces the brain to become insensitive to Leptin. This is what happens in obese people. Luckily this insensitivity is reversible by lowering the circulating level of Leptin. High triglycerides prevent it from reaching the brain and the brain does not respond to Leptin. Reducing triglycerides is another way to reestablish Leptin activity. Insulin plays a part in controlling triglycerides and insulin resistance pushes up triglycerides. The only way out of the vicious cycle is to reduce sugar intake. There are, probably 100 and odd people in the world not producing Leptin at all. These people will be benefitted by Leptin injection. This is, however, is not approved as a method of treatment. Oral substitutes do not work as Leptin is a protein and will be digested in the intestines. However, one should understand Leptin is still experimental and a lot of research is going on to understand its entire functions, working and side effects. It seems to have a beneficial effect on cardiovascular system and bone health. An interesting finding which will affect weight loss is sleep deprivation – less than 7 to 8 hrs reduces Leptin levels increasing and normal 7 to 8 hours were associated with higher Leptin levels.
This is the basis is of Leptin diets which was formulated by a by Leo Galland, M.D. a celebrated practical nutritionist.