Atkins Diet - Ketogenic Diet

Ketogenic Diet

The induction phase of the Atkins diet is a ketogenic diet. In ketogenic diets there is production of ketones that contribute to the energy production in the Krebs cycle. Ketogenic diets rely on the insulin response to blood glucose. Because ketogenic dieters eat few carbohydrates, there is no glucose that can trigger the insulin response. When there is no glucose-insulin response there are some hormonal changes that cause the stored fat to be used for energy. Blood glucose levels have to decrease to less than 3.58 mmol/L (64.5 mg/dl) for growth hormone, epinephrine, and glucagon to be released to maintain energy metabolism. In the adipose cells, growth hormone and epinephrine initiate the triacylglycerol to be broken down to fatty acids. These fatty acids go to the liver and muscle where they should be oxidized and give acetyl-CoA that enters the Krebs cycle directly. However, the excess acetyl-CoA in the liver is converted to ketones (ketone bodies), that are transported to other tissues. In these tissues they are converted back into acetyl-CoA in order to enter the Krebs cycle. Glucagon is produced when blood glucose is too low, and it causes the liver to start breaking glycogen into glucose. Since the dieter does not eat any more carbohydrates, there is no glycogen in the liver to be broken down, so the liver converts fats into free fatty acids and ketone bodies, and this process is called ketosis. Because of this, the body is forced to use fats as a primary fuel source.