Leptin | Medical-Weight-Loss-Guide.com

Leptin is a protein encoded by the OB gene. Its named comes from the Greek word leptos, which means "thin." Its discovery was a major breakthrough in the field of obesity genetics. MRI of the brain

Fat cells make this hormone, which in turn signals a part of the brain called the hypothalamus. This part of the brain controls several bodily functions, including hunger, the metabolism of fats and sugars, and regulation of body temperature.

Leptin is produced more in the evening time and early morning hours. When levels are high, the hypothalamus is signaled that the body has enough energy stored as fat. The hypothalamus decreases the sensation of feeling hungry and increases the body's rate of energy expenditure.

Fasting causes levels to rapidly decrease and activates a starvation response to seek food as well as other bodily reactions:

Theoretically, dieting may initially make your brain feel hungrier than you need to be in order to have a proper energy balance. It may take some time to move out of "starvation mode" where metabolism is suppressed and hunger is increased. Your body would need to adapt its leptin levels to your newly desired weight, at which point, energy use and appetite return to normal.

Some people have mutations in the OB gene, and this causes them to start becoming overweight shortly after being born. They can weigh more than 44 lbs by 1 year old or 110 lbs by 5 years old. They have more than 50% body fat, whereas children normally have 15-25% body fat.

These mutations also lead to several abnormalities of the brain and hormone functions, in particular small gonads (i.e. testicles and ovaries). There are low levels of T-cells, which are a major part of the immune system. This causes them to have a high rate of respiratory infections. Thyroid and growth hormone levels are low as well. The defects are very rare as only 12 cases have been reported in people who have mutations in both of their leptin genes.

Daily injections of synthetic leptin can help these people. Their sense of feeling good from eating diminishes. The hunger subsides, and they do eat less. The gonads grow and function normally. Puberty now takes place as it would in a normal child. There is a small increase in thyroid hormone. Immune function also improves.

Unfortunately, giving it to people who already have normal or high levels does not seem to make them want to eat less. It only benefits those who are deficient in the hormone. However, research is ongoing to try to utilize this signaling system to help people lose weight and maintain weight loss. It may even be able to help with other health issues like high cholesterol, diabetes, and polycystic ovarian syndrome.

It is important you discuss any weight loss or exercise plan with your doctor. Only you and your physician can decide what is best for you. Some people have certain conditions that prevent them from doing all exercises, and goal body weights may be different for different people. You need to discuss all these things with your physician before starting any weight loss or exercise program.