Lovejoy, J.C., Bray, G.A., Lefevre, M., Smith, S.R., Most, M.M., Denkins, Y.M., Volaufova, J., Rood, J.C., Eldridge, A.L., and Peters, J.C.
OBJECTIVE:: To compare the effects of a standard American diet, a traditional low-fat diet, and a low-fat diet containing the fat substitute olestra on risk factors for heart disease and diabetes. DESIGN:: A 9-month, double-blind, randomized, parallel-arm, feeding study comparing three diets: (1) control (33% fat), (2) fat-reduced (FR; 25% fat), and (3) fat-substituted (FS) where olestra replaced 1/3 of dietary fat (33% lipid and 25% digestible fat). Subjects were allowed to adjust their total energy intake as desired, allowing weight to fluctuate. SUBJECTS:: A total of 37 healthy, obese men (age 36.7±1.3?y; body mass index 30.8±0.4?kg/m2). MEASUREMENTS:: Body weight and composition by dual-energy X-ray absorptiometry, blood pressure, serum lipids, lipoproteins, hemostatic factors, glucose, insulin, and leptin at baseline and every 3 months. RESULTS:: The FS group lost 6.27 kg of body weight by 9 months vs 4.0 kg in the control and 1.79 kg in the FR groups. There was a significant diet main effect on cholesterol (P=0.002), low-density lipoprotein cholesterol (P=0.003), and triglycerides (P=0.01), all of which decreased in the FS group but not the other groups by 9 months. Apolipoprotein B (ApoB) increased in the FR and control groups but was unchanged in the FS group (diet main effect P=0.04). High-density lipoprotein (HDL) cholesterol increased in all groups over 9 months (time main effect P=0.0001). Time main effects were also observed for cholesterol, ApoA1, ApoB, Factor VII, diastolic blood pressure, and glucose. After adjustment for % fat loss at 9 months, the effects of diet on change in risk factors remained significant only for triglycerides. DISCUSSION:: Consumption of a low-fat diet containing olestra for 9 months produced significant improvement in cardiovascular risk factors, an effect largely explained by weight loss. Long-term low-fat diet consumption with or without olestra does not decrease HDL cholesterol.International Journal of Obesity (2003) 27, 1242-1249. doi:10.1038/sj.ijo.0802373 [ABSTRACT FROM AUTHOR]