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.
Leptin is produced mostly by our adipose tissue â aka our fat. The level of circulating leptin is directly proportional to the total amount of fat in the body. That means the more fat you have, the greater the amount of leptin you have. It may seem counter-intuitive, but it makes sense in the end when we consider how yo-yo dieting tends to be. It takes some time for your body to adjust to large changes in body fat levels when it comes to leptin. The total AMOUNT of leptin you have is related to your weight. So when you lose a lot of weight quick, via liposuction or serious calorie restriction, your leptin levels plummet.