"Lean" NAFLD: Metabolic Obesity with Normal BMI... Is It in the Genes?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. "Lean" NAFLD represents a patient subpopulation with hepatic steatosis evident on imaging with normal BMI. This paper by Feldman and Eder et al. illustrates the mild but clear metabolic differences and genetic connections in Caucasian lean NAFLD patients compared with obese NAFLD and healthy controls. Their findings highlight key similarities of lean and obese NAFLD compared with lean healthy subjects. This paper characterizes "lean" NAFLD as a unique phenotype with specific genetic associations deserving of further investigation in the greater scheme of elucidating the pathophysiology of fatty liver.