After a fat meal there was a slight rise in oxygen absorption or none at all. After sugar and starch they found a slight initial rise followed by a fall in oxygen absorption in some experiments, and in other experiments they observed a consistent fall in oxygen absorption, with no initial rise. Benedict and Carpenter were unable to explain this fall in oxygen absorption after sugar and starch. They were much surprised to discover that the ingestion of sugar and starch actually could cause a depression of total bodily oxygen absorption below basal requirements. Here are some of the actual experimental results reported by Benedict and Carpenter.
Bananas contain chiefly sugar and starch.
With larger meals the results were even more striking. On the other hand, after 1305 calories of beefsteak there was an increase in oxygen absorption of 40 grams during an eight-hour period. As has, been previously explained, sugar and starch may cause low blood sugar about an hour after eating, and this period of low blood sugar may last from one to three hours. Also, during the period of reduced glucose-oxygen consumption, less heat will be generated and so the body temperature may fall. This reduced heat production during low blood sugar readily explains the presence of subnormal body temperature in certain individuals in the morning before breakfast, and even after meals.