In 1994 at New York’s Rockefeller
University, Dr. Jeffrey Friedman and his research team discovered that the
fat cells of genetically obese mice failed to produce a chemical called
Leptin. Leptin was the first adipokine and the first hormone shown to be
made, exclusively by fat cells. Leptin’s primary function throughout human history has
been to sense body fat for survival during famine. Many scientists believe that
the main evolutionary role of leptin was not to regulate weight or appetite, but
to regulate fertility. Leptin is absolutely necessary for the normal function of
reproductive organs. As fat stores fall, leptin levels drop. At a certain level
of thinness, a woman’s ovaries stop functioning, solely because of leptin
deficiency. This effect is seen today in slim young women with very low body
fat. Leptin lets the brain know when there is enough food available to support
offspring and prevents reproduction when food is scarce.
Leptin will control fat loss
Leptin is a naturally occurring chemical substance that many organisms
produce in response to increasing fat content in the body. In essence, it is
the substance that tells the brain the body is well nourished and can stop
eating, thus functioning as a natural regulator of body weight. In the
1990s, however, scientists noticed that obese individuals are frequently
leptin resistant---their bodies do not respond to the natural regulating
effect of leptin. Correcting this resistance is thought to be one key to
successful, long-term weight loss.
If you are leptin resistant, your own body is essentially sabotaging your
efforts at weight control. In the first place, your brain is not receiving
signals to cease eating when fat stores accumulate, and you'll find yourself
hungry despite knowing rationally that you should be full. To balance your
body's chemistry, you'll need to regulate yourself mentally since your body
can't do it for you. This will take consistent determination and will power.
Exercise even when your body tells you to quit. When the body becomes leptin
resistant, it becomes accustomed to high levels of the chemical in the
blood. A little weight loss can trigger a decrease in leptin, making your
appetite larger and affecting your metabolism negatively. Even though the
body has plenty of fat stores to burn, the muscles cease to do so in
response to decreasing leptin. You may not see results quickly because of
this, and you may find yourself particularly exhausted by exercise. Do it
anyway, because you can't correct leptin resistance without reaching a
Simply stated, leptin is a very powerful and influential hormone discovered
approximately 10 years ago produced by fat cells, that has totally changed
the way that science looks at fat, nutrition, and metabolism in general.
Prior to leptin's discovery, fat was viewed as strictly an energy storage
depot, an ugly one at that and one most everyone was trying to get rid of.
After it was discovered that fat produced the hormone leptin (and
subsequently it was discovered that fat produced other very significant
hormones), fat became an endocrine organ like the ovaries, pancreas and
pituitary influencing the rest of the body and, in particular, the brain. It
tells the brain what to do about life's two main biological goals: eating
I would say now that rather than your brain being in control of the rest of
the body, it is, in fact, subservient to your fat. Your fat, by way of
leptin, tells your brain whether you should be hungry, eat and make more
fat, whether you should reproduce and make babies, or whether to "hunker
down" and work overtime to maintain and repair yourself.
It plays a large role in inflammation, immunity, cardiovascular disease,
diabetes, osteoporosis and all other diseases of aging, and perhaps, aging
Both insulin and leptin work together to control the quality of one's
metabolism and, to a significant extent, the rate of metabolism via nervous
Each and every one of us is a combination of lives within lives. We are made
up of trillions of individual living cells that each must maintain itself.
Even more significantly, the cells must communicate and interact with each
other to form a republic of cells that we call our individual self. It is
the communication among the individual cells that will determine our health
and our life. The communication takes place by hormones. Insulin and leptin
are the major hormones regulating metabolism.
Metabolism can roughly be defined as the chemistry that turns food into
life, and therefore insulin and leptin are critical to health and disease.
Insulin works mostly at the individual cell level, telling the vast majority
of cells whether to burn or store fat or sugar and whether to utilize that
energy for maintenance and repair or reproduction.
Leptin, on the other hand, controls the energy storage and utilization of
the entire republic of cells allowing the body to communicate with the brain
about how much energy (fat) the republic has stored, and whether it needs
more, or should burn some off, and whether it is an advantageous time
nutritionally-speaking for the republic to reproduce or not.
Controlling hunger is one way that leptin controls energy storage. Hunger is
a very powerful and deep-seated drive that, if stimulated long enough, will
make you eat and store more energy. The only way to eat less in the
long-term is to not be hungry.
Leptin also very powerfully influences energy utilization and fat burning
via its effects on the sympathetic nervous system. There is critical
importance for controlling leptin in health and disease.
I want to largely emphasize the importance of reducing grains in your diet
and other non-fiber forms of carbohydrate that readily turn into sugar.
Also, very importantly, I want to stress differences among fats and to
stress eating high quality beneficial fats, and avoiding those that are more
harmful. Protein is used to replace and replenish cellular and body parts
and thus, unlike carbohydrates, is an essential nutrient that must be eaten
to maintain health. If protein is consumed too much, you basically end up
training your body to turn protein into sugar. Sugar produces fat in the
body, the good fats do not create fat in the body.