PNLIP and obesity due to melanocortin 4 receptor deficiency: In addition, the results of another study suggested that the 46,000 Da chitosan was more effective than chitosan of 21,000 or 13,0000 Da in anti-obesity function by inhibiting pancreatic lipase activity (in vitro) and plasma triacylglycerol elevation in the oral lipid tolerance test (Sumiyoshi & Kimura, 2006).