Leptin and Its Failure in Obesity

at 5:00 PM

Leptin,as you may know, is a hormone secreted by fat cells.  After a meal, leptin is secreted by fat cells (adipose tissue) and is transported to the hypothalamus (the hunger center in the brain) to signal that the body is no longer hungry and to refrain from food consumption.  Leptin has to pass the blood brain barrier.  The brain is extremely selective as to what compounds it absorbs.  Many compounds can not pass the blood brain barrier to get to the brain cells but leptin can.

Well, there is evidence that an increase in triglycerides in an individual can inhibit the passage of leptin to the brain.  As a result, leptin can no longer get to the brain, and the negative feedback loop that would normally cease eating is attenuated.  So eating continues. 

Triglycerides are elevated in starvation and obesity.  It is postulated that hypertriglyceridemia (increase in triglyceride levels) evolved as a survival method to keep an individual eating in starvation times.  However, there is also evidence that obesity seems to be doing the same thing by inhibiting the leptin signal, therefore a decrease in eating may be compromised.

The hard and bitter truth:  The best way to keep our leptin working is to PREVENT from gaining weight in the first place.

Something else to think about: it is harder to sustain weight loss than to lose weight.