Abstract
In this experiment the vegetable oil (soybean oil) was used as source of fat component of the experimental high-fat diet in place of the butter fat used in the previous experiment (Report I, Jap. J. Nut., 12, 62, 1955). The fat content in high-fat diet was 34 per cent of the ingested total calories as shown in table I. The experimental periods were divided into following threeperiods: at first high-carbohydrate diet for 3 days, next high-fat diet for 5 days, and at last high-carbohydrate diet for 2 days. During these periods the running of about 7500 meters on the treadmill was performed for 50 minutes after 3 hours of breakfast every day, as shown in table 2. The other experimental methods were the same as in previous experiment.
The results obtained were as follows:
1) In comparison of the work metabolism in high-fat diet period with that in high-carbohydrate diet period, there was no difference in O2 consumption per the same amount of work, volume of expired air and CO2 production were less, accordingly respiratory zuotient lower in high-fat period, as shown in table 3. These results coincided with the previous experiment. It seems that the high fat diet acts favourably upon the work metabolism, as described in previous report.
2) Amounts of urinary acetone bodies per day were in the range of normal value in the previous experiment using the butter fat of about 30 per cent calories, but in this experiment using the vegetable oil of about the same amount as butter the urinary acetonebodies increased apparently as shown in figure 1 and table 4.
It is concluded from the results that high fat diet has an availability to the work metabolism, however the content of the fat of 30 percent calories in the diet is over the optimum amount for Japanese when the vegetable oil was used.
