Liver and gallbladder disease before and after very-low-calorie diets.

Hepatobiliary characteristics of untreated obese patients and those of patients reducing weight through very-low-calorie diets (VLCDs) are reviewed. In untreated obesity, hepatobiliary abnormalities are prevalent. Fatty change is common and may be related to insulin resistance. Moreover, portal inflammation and fibrosis are prevalent findings, also in the absence of alcohol abuse. The liver plays a key role in the hyperinsulinism and hyperlipidemia, and hepatic drug metabolism is influenced by enhanced glucuronidation and sulphatation. Predisposition to gallstone formation can be ascribed to increased biliary cholesterol secretion in concert with changed nucleating factors and altered gallbladder motility. Weight loss by VLCD reduces fatty change but may induce slight portal inflammation and fibrosis. Insulin resistance and pharmacokinetic abnormalities regress. During VLCD the risk of gallstone formation is markedly increased. The deleterious effects described of a rapid weight loss should draw some attention to the liver and biliary tract during VLCD treatment.