II. Diets Containing Approximately Eighty-Seven Per Cent of the Total Caloric Value in the Form of Sucrose, Lard, and Casein, Respectively
Esther M. Greisheimer and
Olga H. Johnson
(From the Department of Physiology, The University of Minnesota, Minneapolis.)
1. After a preliminary observation period on McCollum's stockdiet I, adult rats were fed test diets containing about 87 percent of the total caloric value in the form of sucrose, lardor casein, for about three weeks. The food and water intakeswere determined during both the preliminary and the test period.
2. The gain in body weight was evident on each diet suggestingadaptation.
3. Without knowing the digestibility of each diet,and the absorptivepower of each rat, it is difficult to interpretthe changesin caloric intake during the test period.
4. Thewater intake increased on the high casein diet, and decreasedon the lard and sucrose diets. This is probably determined bythe amount of nitrogenous waste products to be eliminated.
5.The absolute liver weights were in close agreement on thevariousdiets. Considered as per cent of body weight, the liverwaslighter on the high lard diet and heavier on the high caseindiet than on the control diet. Dry weights could not be determined.
6. Liver glycogen was significantly higher on the high sucroseand significantly lower on the lard and the casein, than onthe control diet.
7. An exceedingly close relationship wasfound between the lasttwelve-hour food intake (grams) (8:30P.M. to 8:30 A.M.) andthe liver glycogen content, on the stockdiet.
8. The absence of such close agreement between latefood intakeand glycogen content on the sucrose diet suggestedthat in aliver already saturated with glycogen, more cannotbe stored.
9. Glycogen is probably not readily formed on ahigh lard diet,consequently it did not vary in accordance withthe late foodintake.
10. There was some relation betweenthe late food intake andglycogen content on the high caseindiet. Either it is easierto form glycogen from casein, or thesmall amount of lactosepresent as an impurity in the crudecasein is utilized.
11. From the late intake, expressed asCalories per gram ofbody weight, and the glycogen content expressedas milligramsper gram of liver weight, we have worked out aglycogen formationefficiency scale. If our stock diet possessesan efficiencyof unity, the values are 1.85 for sucrose 0.44for fat and 0.61for casein.