Leptin is a hormone that predominantly derives from fat cells (adipocytes), particularly the white fat cells. It was identified by Friedman et al. in the 1990s. It’s a very important regulator of food intake and all energy homeostatis. It also regulates all other hormones in the body.

When your brain can no longer sense the leptin signal, it has become leptin resistant, which is called leptin resistance. The leptin signal gives your brain information about the energy status of your body, with its estimated 20 trillion cells. These status messages come from the endocrine system, which in turn is regulated by leptin. Resistance to leptin can, among others, result in obesity, diabetes and infertility. You first get leptin when your mother breastfeeds you. So if you weren’t breastfed, you already started from health deficit. The easiest way to check if you are leptin resistant is by doing the mirror test. Are you very fat or very skinny? Chances are high that you are leptin resistant. You can also order a reverse T3 test. Reverse T3 is a competitive inhibitor to the thyroid hormones T3 and T4. Leptin resistance is also shutting down your thyroid gland. As your brain can’t sense leptin properly, it gets a weak signal. Also, the ratio in cerebrospinal fluid of leptin to plasma is decreased, and this indicates that the capacity to transport leptin into the brain is lowered. This makes it think you’re in an energy deficient state, and will down regulate your metabolism accordingly, to save on energy. The brain gets these signals via the hypothalamus, and the hypothalamus is linked to the endocrine system (the system that releases hormones).

This also means that burning fat in your muscles becomes a problem, and why some fat people can’t burn fat with exercise. In lean people there is a one-to-one ratio (molar equivalence) of free circulating leptin and the soluble leptin receptor (SLR). But in morbidly obese people the free leptin is 25 times higher than the SLR. That is to say, the SLR is greatly decreased and the leptin is greatly increased. In people with high leptin levels we also see high levels of white blood cells, low vitamin D levels, an up-regulation of inflammatory cytokines (hormonal regulators) associated with visceral fat (the fat between your organs), and prehypertension (the precursor to high blood pressure).

A protein called amylin is secreted by the beta cells of the pancreas. These beta cells also manufacture insulin (what is also in the drug that diabetics get). However, high levels of leptin fry amylin, which causes the beta cells to stop making insulin. Remember that high levels of leptin leads to leptin resistance, and that leptin resistance occurs five to seven years before becoming insulin resistant. Insulin resistance being a prime reason why diabetics get insulin. Once leptin resistance and insulin resistance both occur long enough, it leads to adrenal resistance. Adrenal resistance also means there is a problem with cortisol. When insulin and cortisol are raised simultaneously and chronically, cancer and chronic diseases can occur. For example, leptin resistance always happens before the development of osteoporosis. Bone is very active as it constantly remodels itself due to the stresses it is placed under. This requires lots of energy. Another process that requires a lot of energy is pregnancy, or fecundity. If you are leptin resistant, it becomes more difficult to get pregnant.

Obesity is not a disease of excess calories, i.e. eating too much. Your body has several ways to deal with excess calories, without making you fat. For instance, leptin modulates the expression of genes that are important for thermogenesis, such as thyrotropin-releasing hormone (TRH). TRH is essential for the synthesis of thyroid hormone. Remember, thyroid hormone is a stimulator of basal metabolic rate. Another being that the body can release excess glucose in the bloodstream via urine.

But wait, thermogenesis, you say? Could it be that the stimulus from cold initiates a set of programs in your body to start burning fat for heat? Wouldn’t that make evolutionary sense? Mankind in its modern form, homo sapiens, is said to have been around for 200.000 to 300.000 years, or 800.000 years if the most recent discoveries pan out. How long has central heating been around? What about the numerous ice ages during that time period? What about the Little Ice Age around the 1700s? Could we use this to correct so-called diseases of civilization? It’s time to stop being Homo Domesticus and start rewilding ourselves.

Further Reading

Becker, Robert O.; Selden, Gary. The Body Electric: Electromagnetism And The Foundation Of Life.

Climate Change Swindle. https://www.modernsamurai.info/ccs/

Gómez-Robles, Aida. Dental evolutionary rates and its implications for the Neanderthal–modern human divergence. Science Advances, Vol. 5 (5), 2019. DOI: 10.1126/sciadv.aaw1268

Homo Domesticus. https://www.modernsamurai.info/homo-domesticus/

Why You Are Still Fat, Even Though You Exercise. https://www.modernsamurai.info/still-fat/

Zhang, Faming, et al. Leptin: Structure, Function and Biology. Vitamins and Hormones, Vol. 71, pp. 345-372, 2005. DOI: 10.1016/S0083-6729(05)71012-8