This study compared the effectiveness of physician advice versus dietitian advice for a fat-reduced diet, and of dietitian advice for a fat-reduced diet versus a soluble fibre-enhanced diet in patients with moderate dyslipidemia. A total of 111 men and women took part in this 26-week, three-group, randomized, clinical trial. The physician advice fat-reduced diet group (n = 38) and the dietitian advice fat-reduced diet group (n = 35) received dietary advice based on the American Heart Association (AHA) Step II guidelines. The dietitian advice soluble fibre-enhanced diet group (n = 38) consumed one-third cup per day of psyllium-containing cereal and was advised to increase soluble fibre intake to over 10 grams a day. LDL-C, TC/HDL-C ratio and body weight reductions over six months were -5.3%, -4.6%, and -1.9%, respectively, regardless of whether a physician or a dietitian provided advice, or whether advice was focused on a fat-reduced diet or a soluble fibre-enhanced diet. Both dietitians and physicians can help moderately dyslipidemic patients make clinically meaningful changes in blood lipid levels. Soluble fibre enhancement of the usual diet leads to similar reductions in LDL-C and TC/HDL-C ratio compared to interventions focused on fat reduction.