Initially after eating a meal, blood glucose levels rise, as do the levels of insulin, which rise sharply. The insulin promotes the storage of excess carbohydrate and fat. During this phase the levels of HGH change little and remain low.

Over the next two hours the blood glucose and the insulin levels begin to decline, while those of HGH begin to rise slowly. At this stage HGH is promoting the buildup of muscle, its function enhanced by the presence of insulin.

In the last stage, four hours after eating, the blood glucose levels remain low, the insulin levels hit their lowest point, but in contrast, the levels of HGH reach and remain at their highest point. During this phase it is mainly HGH alone that functions in promoting the burning of fat stores in the body. Finally, after six hours, the HGH levels begin to drop as well.

Given Christiansen's explanation of what is occurring with respect to the levels of these three substances, one might be tempted to speculate just a little as to how this might offer an explanation concerning the raised HGH levels that occur during fasting.

Could it be that since there is no food coming into the digestive system, the blood glucose levels then remain low, and as a consequence, so do the insulin levels? Perhaps, with the body still needing energy for its day to day activities, and if the function of HGH in this context is in facilitating the burning of fat stores in the body, then that function would require that HGH continue to be present at high levels. Which is exactly where the levels of HGH are found to be during fasting.

On the other hand, perhaps other explanations will be found that demonstrate the situation to be otherwise.