Forty-two obese [body mass index (kg/m(2)): 30 +/- 5; weight: 92.9 +/- 10.1 kg] men aged 60 +/- 9 y were recruited to determine the effects of an American Heart Association (AHA) diet, with and without weight loss, on lipoprotein lipids. All subjects entered a 3-mo, weight-maintaining AHA diet followed by either a 9-mo weight-loss (AHA + WL, n = 28) or a 9-mo AHA plus weight-maintenance (AHA + WM, n = 14) interven tion. Baseline diets were high in fat (35 +/- 6% of energy) and cholesterol (380 +/- 158 mg/d), and low in dietary fiber (18 +/- 5 g/d). The 3-mo AHA diet resulted in an 11% decrease in plasma triacylglycerol (1.83 +/- 0.15 to 1.47 +/- 0.08 mmol/L, P < 0.05), a 16% decrease in plasma cholesterol (5.39 +/- 0.96 to 4.56 +/- 0.91 mmol/L, P = 0.0001), a 17% decrease in high-density-lipoprotein (HDL) cholesterol (1.09 +/- 0.23 to 0.91 +/- 0.18 mmol/L, P = 0.0001), and a 14% decrease in low-density-lipoprotein (LDL) cholesterol (3.47 +/- 0.83 to 2.98 +/- 0.78 mmol/L, P = 0.0001). The AHA + WL group lost 9.8 +/- 4.3 kg (P < 0.001, n = 28) and further reduced plasma triacylglycerol by 17% (P < 0.05), total cholesterol by 4% (P < 0.05), LDL cholesterol by 7% (P < 0.05), and significantly increased HDL cholesterol by 15% (P < 0.05) when compared with their 3-mo AHA-intervention values. These changes were significant (P < 0.05) when compared with the AHA + WM group, in whom lipoprotein lipids did not change. Thus, the addition of weight loss to the AHA Step I diet prevents the decrease in HDL cholesterol seen with a 3-mo AHA dietary intervention, and has complementary effects in lowering plasma cholesterol, LDL cholesterol, and triacylglycerol concentrations in obese middle-aged and older men.
