Responses of inflammatory markers to a low-fat, high-carbohydrate diet: effects of energy intake.

BACKGROUND: Inflammation contributes to atherogenesis. Dietary fats may be proinflammatory.
OBJECTIVE: The objective was to determine whether energy intake modulates the effects of low-fat, high-carbohydrate intakes on inflammatory markers.
DESIGN: Twenty-two healthy postmenopausal women with a mean (+/-SD) age of 61 +/- 11 y, who were not receiving hormone replacement therapy, were fed eucaloric diets to reduce their fat intake from 35% to 15% of energy. Next, the women consumed a 15%-fat ad libitum diet under free-living conditions. Serum highly sensitive C-reactive protein, interleukin 6, HDL serum amyloid A, and adiponectin concentrations were measured at the end of the eucaloric and ad libitum low-fat, high-carbohydrate intakes.
RESULTS: The eucaloric diet decreased adiponectin from 16.3 +/- 2.1 to 14.2 +/- 2.0 mg/L (P < 0.05) and increased triacylglycerol from 131 +/- 11 to 164 +/- 14 mg/dL (P < 0.01). The ad libitum low-fat diet caused 6 kg weight loss and decreased highly sensitive C-reactive protein from 4.3 +/- 0.6 to 2.5 +/- 0.5 mg/L (P < 0.01), decreased HDL serum amyloid A from 10.3 +/- 1.8 to 5.7 +/- 1.3 mg/L (P < 0.001), increased adiponectin from 14.2 +/- 2.0 to 16.3 +/- 1.7 mg/L (P < 0.05), and decreased triacylglycerol from 164 +/- 14 to 137 +/- 15 mg/dL (P < 0.05).
CONCLUSION: During the eucaloric phase, the low-fat, high-carbohydrate diet exerted unfavorable effects on the inflammatory markers. In contrast, the ad libitum low-fat, high-carbohydrate intake caused weight loss and affected inflammatory markers favorably. Thus, the energy content of a low-fat, high-carbohydrate diet determines changes in inflammatory markers.