Effect of Prolonged Fasting and Ketogenic Diet on Levels of Blood Lipids and Ketones in Obese Children

Blood levels of glucose, ketones and various lipids have been studied in 31 obese and 10 normal children during prolonged fasting (23 hrs) and a week on a subcaloric high fat diet. The obese group has higher fasting values of all components analysed, except blood sugar. A statistically significant difference is obtained for the glycerol and ketone levels. The obese show blood-changes later than the normal subjects, have a less pronounced rise in FFA, but a similar rise in blood ketones. The obese subjects had an impaired glucoseto-lerance, that became more pronounced under the influence of the ketogenic diet. The pattern of response in various blood components among the obese children was best correlated with the time of onset of overweight, i.e. a greater deviation from the controls after a long duration of obesity. The metabolic abnormalities among overweight children as measured in this study are interpreted as being suggestive of an adaptation to obesity as such, duration of overweight playing a central role.