The underlying theory of blood type diets is that people with different blood types digest lectins differently, and that if people eat food that is not compatible with their blood type, they will experience many health problems.
Leptin is a potent stimulator of the immune system. Leptin receptors on monocytes cause the release intracellularly of STAT3 which cause the monocytes to release IL-6, IL-12 and TNF alpha. The IL-6 goes to the liver and increases production of CRP.
Hormone: Leptin. One of the many hormones produced by your fat cells is leptin, which plays a role in appetite control. Research has found that excess body fat can cause a condition known as leptin resistance, which means your brain isn't affected by leptin even though your body contains higher levels of it.