Background: Since obesity is associated with chronic oxidative and inflammatory stress and high fat high carbohydrate meal induces significant oxidative and inflammatory stress in normal subjects, we have now hypothesized that the intake of a high fat high carbohydrate meal would result in a greater and more prolonged oxidative and inflammatory stress in the obese than in normal subjects.

Methods: Ten normal weight and eight obese subjects were given a high fat high carbohydrate meal after an overnight fast. Blood samples were collected at baseline and hourly following the meal for 3 hours (h).

Results: Reactive oxygen species (ROS) generation by mononuclear cells increased significantly by 2h in both groups but continued to increase significantly at 3 hr in the obese subjects while in normal subjects it returned to baseline. Levels of p47^phox increased significantly (by 81±26%) at 3h in obese individuals (P<0.05), while there was no significant change in p47^phox in normal subjects. Nuclear Factor-b (NF-B) DNA binding in MONONUCLEAR CELLS increased significantly (by 48±58%, P<0.036) at 2h but not at 3h in normal subjects while in the obese NF-B increased significantly at both 2h and 3h (by 36±57% and 42±63%, respectively, (P<0.004). Matrix metalloproteinase (MMP)-9 concentrations were significantly higher in the obese at baseline (580±103.9 vs. 373±30.03 ng/ml, P<0.05) and increased to significantly greater concentrations after the meal than that in the lean.

Conclusions: High fat high carbohydrate meal induced a significantly more prolonged and greater in the obese. This may contribute to the increased atherogenic risk in obesity.