On the basis of studying the dynamics of losses in the reserve fat and active body mass during a catabolic phase of the burn disease, in 124 sufferers with the burns of 5 to 80% of the body surface, a classification of the severity degree of lipido-protein deficiency, which distinguishes a compensated, subcompensated and decompensated grade and subdivides the latter into the reversible and irreversible forms, is suggested. The classification permits to assess more objectively the severity of the state and prognosis in burned patients, and as well to define purposefully the methods for correction of the revealed disorders.