This study investigates the contribution of visceral adipose tissue lipolysis to hepatic free fatty acid (FFA) delivery in humans with varying degrees of obesity. Using isotope dilution and hepatic vein catheterization techniques, the researchers examined FFA kinetics in obese and lean individuals. The results show that FFA concentrations were approximately 20% higher in obese men and women compared to lean individuals. The contribution of splanchnic lipolysis to hepatic FFA delivery ranged from less than 10% to almost 50%, increasing with visceral fat content, particularly in women. Leg and splanchnic tissues contributed a greater portion of systemic FFA release in obese individuals. The study concludes that visceral adipose tissue lipolysis contributes more to hepatic FFA delivery in individuals with greater visceral fat, and this effect is more pronounced in women than in men. These findings have implications for understanding the regulation of hepatic glucose and lipoprotein metabolism in obesity.This study investigates the contribution of visceral adipose tissue lipolysis to hepatic free fatty acid (FFA) delivery in humans with varying degrees of obesity. Using isotope dilution and hepatic vein catheterization techniques, the researchers examined FFA kinetics in obese and lean individuals. The results show that FFA concentrations were approximately 20% higher in obese men and women compared to lean individuals. The contribution of splanchnic lipolysis to hepatic FFA delivery ranged from less than 10% to almost 50%, increasing with visceral fat content, particularly in women. Leg and splanchnic tissues contributed a greater portion of systemic FFA release in obese individuals. The study concludes that visceral adipose tissue lipolysis contributes more to hepatic FFA delivery in individuals with greater visceral fat, and this effect is more pronounced in women than in men. These findings have implications for understanding the regulation of hepatic glucose and lipoprotein metabolism in obesity.