Chitosan oligosaccharide capsules can inhibit hepatic lipid synthesis by prominently regulating the gene expressions of SREBP-1c, FAS, ACC, HMGCR, and adiponectin to improve hepatic steatosis and lipid metabolism disorder, thereby exerting hepatoprotective and anti-obesity effects (Figure 6). This evidence concerns the gene FAS and obesity due to melanocortin 4 receptor deficiency.