Relatively large amounts of fat were ingested in the diet of butter and potato chips. The latter is a common food material in America and consists of thin slices of raw potato fried in deep fat. As a rule potato chips have a composition of approximately 5 per cent protein, 40 per cent fat, and 42 per cent carbohydrate, with a fuel value of 5.5 calories per gram. Details regarding the composition of those used in our study may be found in table 50.1 It will be seen from these figures that the potato chips not only served as a vehicle for the butter, but also supplied a considerable proportion of the energy in the form of fat. It was hoped that the subjects of the experiments would be able to take large amounts of butter with the potato chips, but unfortunately this was possible in only a few experiments.

4See p. 124.

E. H. B., March 19, 1907

The subject of the first experiment with this diet was able to eat only 83 grams of butter with 233 grams of potato chips. The basal value selected for comparison is an average of values obtained in two experiments made a week or 10 days previous to the experiment with butter. The results of the experiment are given in table 191. Notable increases were obtained in the carbon-dioxide production for the three 2-hour periods after the taking of the food; considerable increments were also found for oxygen consumption and heat production. It may therefore be considered that the fat diet of butter and potato chips had a decided influence upon the metabolism. Although 22 per cent of the energy in the diet was derived from carbohydrates, it is hardly probable that the amount present played a very important part in the metabolism.

Table 191. - E. H. B., March 19, 1907. Sitting. (2-Hour Periods). Butter And Potato Chips

Amounts, 83 grams butter, 233 grams potato chips; nitrogen, 2.18 grams; total energy, 1,943 cals. Fuel value: Total, 1,924 cals.; from protein, 3 p. ct.; from fat, 75 p. ct.; from carbohydrates, 22 p. ct. Basal values (March 7 and 13, 1907): CO2, 58 grams; O2 48 grams; heat, 179 cals.

1Subject ate food in about 30 minutes.

2Heat eliminated corrected for change in body-weight, but not for change in body-temperature.

A. H. M., March 25, 1907

The largest amount of butter used in this series of experiments was taken by A. H. M., who was able to eat 243 grams with 211 grams of potato chips. The available energy of the food was over 3,000 calories. Of this energy, 85 per cent was derived from fat and but 13 per cent from carbohydrates. The basal value was obtained in two experiments two or three weeks previous to the experiment with butter. Positive increments of considerable magnitude were observed in the three factors of the metabolism with no indication of a return to the basal value at the end of the fourth 2-hour period (see table 192). The subject, who has always been considered very satisfactory, maintained approximately uniform muscular activity throughout the entire experiment. We may consider, therefore, that the increment measured is clearly due to the fat diet and that the ingestion of butter and potato chips in these proportions had a decided positive effect upon the metabolism.

Table 192. - A H. M., March 25, 1907. Sitting. (2-Hour Periods). Butter And Potato Chips

Amounts, 243 grams butter, 211 grams potato chips; nitrogen, 2.24 grams; total energy, 3,222 cals. Fuel value: Total, 3,202 cals.; from protein, 2 p. ct.; from fat, 85 p. ct.; from carbohydrates, 13 p. ct. Nitrogen in urine, 0.89 gram per 2 hours.1 Basal values (March 6 and 9, 1907): CO2, 51 grams; O2, 46 grams; heat, 164 cals.

1Sample included amount for about 1 \ hours preceding eating of food.

2Subject ate food in 37 minutes.

3Heat eliminated corrected for change in body-weight, but not for change in body-temperature.

A. H. M., May 15, 1907

This second experiment was made with A. H. M. about 7 weeks later; the details are given in table 193. He was able to take only about half as much butter as in the previous experiment, with a proportionate amount of potato chips. The exact amounts taken were 113 grams of butter and 105 grams of potato chips. Even with this reduced amount of fat in the diet, there was a positive increment in carbon-dioxide production and heat production in the first two periods. The values obtained for oxygen consumption were erratic, the total effect being 10 grams less than the basal value. Since both carbon-dioxide production and heat production showed a positive increment, it is reasonable to conclude that this diet had a definite effect upon the metabolism. As the respiratory quotients were much higher than would be expected with a fat diet, it is probable that the determinations of the oxygen consumption were erroneous.

A. W. W., April 25,1907

The amount of butter eaten by this subject, 85 grams, was approximately the same as that taken by E. H. B., but the amount of potato chips was smaller, as he used but 104 grams or about the same amount as that taken by A. H. M. in his last experiment. The details of the experiment are given in table 194. The increment in the metabolism is small in amount but is nevertheless distinctly positive, although the basal value for the heat production was reached in the third period and presumably in the same period for the carbon-dioxide production.

Table 193. - A. H. M., May 15, 1907. Sitting. (2-Hour Periods). Butter And Potato Chips

Amounts, 113 grams butter, 105 grams potato chips; nitrogen, 1.11 grams; total energy, 1,512 cals. Fuel value: Total, 1,503 cals.; from protein, 2 p. ct.; from fat, 85 p. ct.; from carbohydrates, 13 p. ct. Basal values (March 6 and 9, 1907): CO2, 51 grams; O2, 46 grams; heat, 164 cals.

1Subject ate food in 28 minutes.

2Sample included amount for about 21 hours preceding eating of food.