The research study comprised 3 groups of laboratory rats (n = 13) fed as follows: group I: standard fodder (Labofeed B) containing i.a. whole grains of wheat and corn; group II: modified fodder where, compared to the standard fodder, about 84 % of whole wheat grains were replaced with wheat flour type 500, and 50 % of corn grains present therein with sucrose; group III: modified fodder supplemented with Ca, Mg, Zn, and Cr the quantities of which made up differences after the components were interchanged. Percent content of other macro-components in both fodder types were identical. It was found that supplementing the fodders caused the consumption thereof to decrease and ipso facto the intake of mineral components to decrease, too. However, the increases in body weights of animals in that group were higher as was the accumulation level of visceral fat tissue. In that group, the content of fat increased significantly (p ≤ 0.01) and the content of protein in muscle tissue decreased significantly (p ≤ 0.01). No significant effects of the fodder supplementation applied was reported on the concentration of analyzed mineral components in blood serum and on their content in muscle tissue.