An experiment was conducted to evaluate the effects of feed restriction and sex class on the intake and digestibility of nutrients as well as meat fatty acid profiles in Santa Ines lambs. Thirty lambs with initial body weights of 13 ± 1.49 kg and ages of 60 d were used in a completely randomized study with a 3 × 2 factorial arrangement consisting of three feeding levels (0 or ad libitum, 30%, and 60% feed restriction) and two sex classes (15 intact male and 15 castrated male), comprising five animals in each treatment. The experimental trial lasted 100 d. Increased feed restriction levels resulted in lower intake (P < 0.001) and higher digestibility of nutrients. There were decreases (P < 0.05) in the excretion of nitrogen compounds and purine derivatives when feed restriction increased. The feed restriction decreased (P < 0.05) the concentrations of C18:2n6 and C18:3n3 in the meat but did not affect the C18:2c9t11. The ratio of polyunsaturated fatty acids:monounsaturated fatty acid was higher in the 60% feed restriction. The results suggest that feed restriction improves nutrient utilization efficiency. The feed restriction up to 30% leads to a higher concentration of saturated fatty acids in meats.