Leptin resistance typically occurs when the body develops an intolerance to the hormone leptin. The body's fat cells normally produce this hormone. When the body is appropriately sensitive to leptin, the hormone can help prevent obesity by signalling to the brain that the stomach is full after a meal. People who suffer from leptin resistance usually don't interpret these neural signals correctly, or they may be experiencing a reduced number of leptin receptors in the brain, which is often a normal result of the aging process. Leptin resistance can stop the brain from recognizing that the stomach is full, leading to continued feelings of hunger and overeating. Leptin resistance usually leads to the development of belly fat, which can raise the risk of obesity, diabetes, and heart disease.
Chronic overeating can cause leptin resistance because it can cause the accumulation of fatty tissues on the body. Fat cells produce leptin, so, the more fat cells a person's body has, the more leptin that person's body produces. When the brain becomes inundated with high levels of leptin, it may begin to ignore the hormone's signals. Some experts believe that the cycle of overeating, weight gain, continued overeating, and continued weight gain begins this way. More fat cells produce more leptin, which leads to higher resistance, and more weight gain.
Some researchers believe that high levels of leptin in the body can damage the hormone's ability to function properly. Others believe that advancing age can contribute to leptin resistance. The brain's leptin receptors may naturally decrease in number as the body ages. This can inhibit the brain's ability to receive appropriate signals of fullness from the action of leptin. This may be why weight gain becomes more likely as one grows older.
Leptin is considered crucial to the prevention of overeating, weight gain, and obesity, because it typically tells the brain when the stomach is full. Feelings of fullness and satiation occur, and the person most likely stops eating. When the brain fails to receive appropriate satiety signals due to leptin resistance, feelings of hunger are likely to continue even after the stomach is full. As a result, overeating and weight gain are likely.
Most experts believe that leptin resistance can be diminished with regular fat-burning exercises. Shedding body fat can help lower leptin levels, to break the cycle of overeating and weight gain.