Effect of Acute Negative and Positive Energy Balance on Basal Very-Low Density Lipoprotein Triglyceride Metabolism in Women

Background: Acute reduction in dietary energy intake reduces very low-density lipoprotein triglyceride (VLDL-TG) concentration. Although chronic dietary energy surplus and obesity are associated with hypertriglyceridemia, the effect of acute overfeeding on VLDL-TG metabolism is not known. Objective: The aim of the present study was to investigate the effects of acute negative and positive energy balance on VLDL-TG metabolism in healthy women. Design: Ten healthy women (age: 22.0+/-2.9 years, BMI: 21.2+/-1.3 kg/m(2)) underwent a stable isotopically labeled tracer infusion study to determine basal VLDL-TG kinetics after performing, in random order, three experimental trials on the previous day: i) isocaloric feeding (control) ii) hypocaloric feeding with a dietary energy restriction of 2.89+/-0.42 MJ and iii) hypercaloric feeding with a dietary energy surplus of 2.91+/-0.32 MJ. The three diets had the same macronutrient composition. Results: Fasting plasma VLDL-TG concentrations decreased by similar to 26% after hypocaloric feeding relative to the control trial (P = 0.037), owing to decreased hepatic VLDL-TG secretion rate (by 21%, P = 0.023) and increased VLDL-TG plasma clearance rate (by similar to 12%, P = 0.016). Hypercaloric feeding increased plasma glucose concentration (P = 0.042) but had no effect on VLDL-TG concentration and kinetics compared to the control trial. Conclusion: Acute dietary energy deficit (similar to 3MJ) leads to hypotriglyceridemia via a combination of decreased hepatic VLDL-TG secretion and increased VLDL-TG clearance. On the other hand, acute dietary energy surplus (similar to 3MJ) does not affect basal VLDL-TG metabolism but disrupts glucose homeostasis in healthy women.