Effect of Exercise and the Specific Dynamic Action of Fat in Obese Subjects.

Abstract

The effect of a meal containing 100 gm. of butter and 50 gm. of olive oil mayonnaise, alone, and with exercise, has been determined in 2 normal and 4 non-diabetic obese subjects.

The metabolism was determined by collection and analysis of the expired air; after determining the basal metabolic rate the subjects were usually exercised while still in the post-absorptive state and before the ingestion of the fat meal; this gave the post-absorptive metabolism both at rest and in exercise. They were then given the 150 gm. of fat and the resting and exercise metabolism was determined, usually once an hour for 7 to 8 hours.

The exercise consisted of having the subject lift the lower extremities, while lying on the back and connected with the spirometer, rhythmically and alternately so as to touch with the toes a board placed a given distance above the foot of the bed. The rhythm was maintained by the use of a metronome which was usually set at about 76 beats per minute, so that a lower extremity was lifted 19 times per minute. This exercise increased the metabolism from 2 to 3 times. The subjects exercised for 2 minutes before collection of the expired air was begun; and this was continued for 5 or 6 minutes, depending on the degree of fatigue produced.

In 2 normal subjects and one of the obese there was a slight initial rise in the resting respiratory quotient following the ingestion of the fat; this was followed by a gradual fall, which, at the end of 6 to 7 hours reached a level lower than the resting quotient.

In 3 of the 4 obese subjects there was a rise in the resting quotient following the fat meal.