In-depth investigation of the mechanism of overweight, it was found that the chronic mild inflammation and altered intestinal microbes play an important role in obesity (18, 19), and adipose tissue was not only considered as an inert energy store but also secretes various adipokines (such as, leptin, adiponectin, and lipase) and cytokines [such as, tumor necrosis factor-alpha (TNF-α), interleukins (ILs), and monocyte chemotactic protein (MCP)]. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.