Abstract
It has been shown in animal experiments that changing the time distribution of food intake causes a change in the metabolic state, and gorging is more likely to cause obesity and enhance lipogenesis, compared with nibbling. This effect of gorging has been ascribed to the difference in specific dynamic action (SDA).
The present study was undertaken to clarify the influence of a change in feeding frequency and fasting upon IRI and HGH as well as blood sugar and FFA levels. Five healthy males and three healthy females were used as subjects. A prescribed diet of 2238 calories containing 93 gm of protein, 59.7 gm of fat and 330 gm of carbohydrate was given in two, three and six meals a day. In the study of the fasting state, the subjects were made to fast for 36 hours. The following results were obtained.
1. Blood sugar and IRI increased after each meal, but the increase was greater after the evening meal than morning and afternoon meals. The highest levels were obtained after the evening meal on 2 meals a day schedule. They declined gradually during fasting.
2. There was no difference in the mean 24-hour blood sugar levels regardless of the frequency of food intake, whereas the mean 24-hour IRI levels became higher as the daily intake was divided into fewer portions.
3. FFA declined after each meal and rose thereafter, and remained high during the night. FFA levels tended to be higher as frequency of meals decreased.
4. The fluctuation of HGH varied from one individual to another, but, in general, there was a larger fluctuation during fasting than during the day when the subjects took meals. There was no remarkable difference in the type of HGH changes dependent upon the frequency of meals, however.
The results appear to indicate that an increased release of insulin induced by food intake after a longer interval following the previous meal plays an important role in the mechanism o1 SDA of the meal and in causing obesity in gorging.
