Growth hormone or 'GH' is a very important hormone that regulates the release of fat from your body stores so that it can be used as a fuel source.
Traditionally we have been taught that to burn fat you need to keep our insulin levels 'normal' or 'under control'. It turns out that the release of body fat is controlled by GH....
Intermittent fasting of course increases GH levels as explained here
I like Brad's eat stop eat book on fasting which explains this among other stuff..
Lots of us in the paleo / evolutionary fitness community are regularly practising fasting. Richard often fasts as does Keith - pictured below.
Keith - in this post explains how fasting has added the finishing touch to his physique:
Essentially, we are designed to be intermittent eaters, but continuous metabolizers. We operate in a slight energy surplus during the day, followed by a negative energy balance during the night. In a healthy, lean individual, energy pool stores are constantly turning over; individuals whose insulin level is chronically high, however, cannot adequately access fat stores and, therefore, for them, the fat continues to accumulate, unabated. Insulin resistance can therefore be considered a survival mechanism, in the fact that it develops as a result of the body’s cells’ requiring protection against the continual onslaught of excess nutrients; a protection triggered due to the cells being already stressed from excessive nutrient content. The excess nutrient intake also serves to shut down autophagy, the consumption of damaged tissues within the muscle cell which fuels repair and regeneration. Growth Hormone release is stunted, and muscle gene expression is down regulated. The ancestral environment did not support chronic, elevated nutrient ingestion, nor was there ever “a window of feeding opportunity” subsequent to a bout of energy expenditure (exercise, for us modern-day Paleolithics) to shovel in carbohydrate replacement drinks and protein powders.
Ideally, we’d eat only when the energy substrates in the blood fall to the point of triggering a need for replenishment. The true hunger signal is an elegantly simple energy management system, and one that you would, in fact, expect from evolution. Contrary to the continual drumbeat of mainstream “experts”, there is no “set point” level for body fat, body mass or metabolism. What evolution has endowed us with is a simple feeding strategy that endeavors to keep us on a random energy intake-to-expenditure path that favors the survival (and thriving, if conditions are right) of the organism. Now, if we’d only get out of the way and let this fabulous mechanism take its course.
Brad's book is a great introduction to the science behind all this.