This study compared the effect of a low-fat, ad libitum, complex- carbohydrate (LFAL) diet with a low-energy (LE) diet on weight loss over 6 mo in moderately obese women. Weight loss was 4.4 kg in the LFAL (n = 47) and 3.8 kg in the LE (n = 42) participants. The difference was not statistically significant. The LFAL participants decreased percent energy from fat by 13%, increased percent energy from carbohydrate by 11.4%, and reduced energy intake by 1654 kJ. The corresponding values in the LE group were 3.8%, 3.5%, and 1991 kJ, respectively. Changes in fat and carbohydrate energy were significantly different by treatment (P < 0.0001). Palatability, satiety, and quality of life (QOL) improved in the LFAL group but diminished in the LE group. Palatability and QOL changes were significantly different by treatment (P < 0.029 and P < 0.048, respectively). It is concluded that an LFAL diet can result in substantial weight loss and is associated with improved palatability and QOL compared with an LE diet.