APOB and obesity due to melanocortin 4 receptor deficiency: Numerous studies demonstrate increased postprandial plasma TGs and apolipoprotein B48 (apoB48) levels in patients who are obese and/or have type 2 diabetes due to chylomicron overproduction.4 The last decade has seen extraordinary advances in our understanding of the role of abnormal intestinal lipid absorption in the development of obesity and metabolic diseases, highlighting the intestine as a gatekeeper in the flux of dietary fat into the circulation.