To assess the effect of some strategies for body weight reduction on the nutritional status of rats.Thirty-six rats were divided into 6 equal groups: sedentary (S100), trained (T100), sedentary + 25% food restriction (FR) (S75), sedentary + 50% FR (S50), trained + 25% FR (T75), and trained + 50% FR (T50). Body composition and serum insulin-like growth factor-1, albumin, and IgG concentrations were determined and the delayed-type hypersensitivity test was applied.Insulin-like growth factor-1 (IGF-1) concentration was lower in the S50 group and higher in the T75 and T50 groups compared with the S100 group. The response to the delayed-type hypersensitivity and IgG concentrations were lower in the S50 and T50 groups; however, the difference was nonsignificant.Strategies for weight reduction such as FR (50%), combined or not with physical exercise, may be harmful to the nutritional status of rats.