INTRODUCTION In regard to the dietary of tuberculous patients medical opinion has fluctuated within wide limits. The extent of this fluctuation may be seen by an examination of the data collected by Fisher,1regarding the dietaries given patients by ninety-five of the leading sanatoriums of the world. In this list the total number of calories fed daily ranges from a maximum of 5,500 to a minimum of 2,140. The number of grams of protein varies from 60 to 190 per diem. To the practical physician, who is faced with the problem of selecting the best type of dietary to prescribe for tuberculous patients, the problem is quite bewildering. To make the selection it is necessary to know, first, the total energy transformations in such patients and, second, the extent of destruction of protein by the toxins of the disease and the minimum amount of protein which must be given to