Ketogenic diet, ketosis, and the upsides
When consuming a diet low in carbohydrates, there are a number of hormonal changes that place. These changes include: a reduction in circulating insulin levels; and an increase in glucagon. These changes, and the indirect effects of these changes, favour gluconeogenesis – the creation of glucose from non-carbohydrate sources, such as pyruvate, glycerol or amino acids (protein). Where carbohydrates are restricted to very low levels, the body reduces its reliance on glucose in order to reduce the need for gluconeogenesis to occur. In turn, the liver begins to produce ketone bodies (at a much greater rate than under normal conditions). These ketone bodies can then be used as energy, even by organs such as the brain, minimising the need for glucose for fuel. This is when the body enters a state of ketosis, and typically results when somebody adhere’s to a ketogenic diet.
During a low carbohydrate intake, the regulated and controlled production of ketone bodies causes a harmless physiological state known as dietary ketosis. This is very different from the potentially life-threatening condition ketoacidosis, typically a complication of type 1 diabetes in which massive amounts of ketone bodies are produced in an unregulated and uncontrolled fashion. Ketone bodies can be detected in urine in such situations, and the high blood acidity can overwhelm the bodies buffering system. Implementation of the ketogenic diet, plus a small amount of insulin, however, can be used effectively to manage type 1 diabetes.
For those of you interested in learning more about the ketogenic diet, WATCH THIS VIDEO. Jeff Volek – a prominent author on the subject of low carbohydrate/high fat or ketogenic diets – does a nice job of discussing the physiology and metabolic issues regarding ketogenic diets
The ketogenic diet – a diet that induce a state of ketosis – may be beneficial in a number of situations and disease states. One instance in which ketosis is beneficial is in people who suffer from epilepsy. In addition, the ketogenic diet may also be beneficial for both type 2 & 1 diabetics, and possibly even in people with certain forms of cancer. This is along with more common scenarios such as insulin resistance, PCOS and obesity. Although research will continue to shed more light on the ketogenic diet, it does appear as though a significant restriction of carbohydrates can be beneficial for some individuals, in some situations.
NB: I perhaps ‘wouldn’t’ advocate ketogenic diets for athletes, due to the physiological need for carbohydrates to fuel highly intense activity. Instead, some form of carbohydrate restricition may actually be beneficial, which the articles HERE & HERE discuss. There are, however, reports of ultra endurance athletes succeeding on ketogenic diets. Conversely, there are many more instances of athletic success with a high carbohydrate diet.
Ketogenic diet – summary
Ketosis is a normal consequence of significant carbohydrate restriction. Different individuals can enter ketosis at slightly different intakes of fat & protein, however, it is generally well accepted that carbohydrates must be kept to a minimum. Interestingly, it appears as though the body can survive without the need for carbohydrate consumption. For example, in states of a low carbohydrate intake, the body produces and utilizes ketone bodies as an energy substrate. Moreover, the body has mechanisms for turning substrates ‘other’ than glycogen into glucose. Lastly, there may be instances where the ketogenic diet is most beneficial.