De novo lipogenesis during controlled overfeeding with sucrose or glucose in lean and obese women

Background: The results of previous studies suggest that de novo lipogenesi s may play an important role in the etiology of obesity, particularly durin g overconsumption of different carbohydrates. Objective: We hypothesized that de novo lipogenesis. would increase during overfeeding, would vary depending on the type of carbohydrate consumed, and would be greater in obese than in lean women. Design: De novo lipogenesis was measured during 96 h of overfeeding by 50% with either sucrose or glucose and during an energy balance treatment (cont rol) in 8 lean and 5 obese women. De novo lipogenesis. was determined by me asuring the amount of deuterium incorporation into plasma triacylglycerols. Fat and carbohydrate balance were measured simultaneously by continuous wh ole-body calorimetry. Results: De novo Lipogenesis did not differ significantly between lean and obese subjects, except with the control treatment, for which de novo lipoge nesis. was greater in the obese subjects. De novo lipogenesis was 2- to 3-f old higher after overfeeding by 50% than after the control treatment in all subjects. The type of carbohydrate overfeeding (sucrose or glucose) had no significant effect on de novo lipogenesis in either subject group. Estimat ed amounts of absolute VLDL production ranged from a minimum of 2 g/d (cont rol) to a maximum of 10 g/d after overfeeding. This compares with a mean fa t balance of approximate to 275 g after 96 h of overfeeding. Individual sub jects showed characteristic amounts of de novo lipogenesis, suggesting cons titutive (possibly genetic) differences. Conclusion: De novo lipogenesis increases after overfeeding with glucose an d sucrose to the same extent in lean and obese women but does not contribut e greatly to total fat balance.