Monday, January 14, 2008

History of the Ketogenic Diet (by Lyle McDonald)

History of the Ketogenic Diet (by Lyle McDonald):

Other clinical conditions
Epilepsy is arguably the medical condition that has been treated the most with ketogenic diets (1-3). However, preliminary evidence suggests that the ketogenic diet may have other clinical uses including respiratory failure (6), certain types of pediatric cancer (7-10), and possibly head trauma (11) . Interested readers can examine the studies cited, as this book focuses primarily on the use of the ketogenic diet for fat loss.

Obesity
Ketogenic diets have been used for weight loss for at least a century, making occasional appearances into the dieting mainstream. Complete starvation was studied frequently including the seminal research of Hill, who fasted a subject for 60 days to examine the effects, which was summarized by Cahill (12). The effects of starvation made it initially attractive to treat morbid obesity as rapid weight/fat loss would occur. Other characteristics attributed to ketosis, such as appetite suppression and a sense of well being, made fasting even more attractive for weight loss. Extremely obese subjects have been fasted for periods up to one year given nothing more than water, vitamins and minerals.

The major problem with complete starvation is a large loss of body protein, primarily from muscle tissue. Although protein losses decrease rapidly as starvation continues, up to one half of the total weight lost during a complete fast is muscle and water, a ratio which is unacceptable.

In the early 70's, an alternative approach to starvation was developed, termed the Protein Sparing Modified Fast (PSMF). The PSMF provided high quality protein at levels that would prevent most of the muscle loss without disrupting the purported 'beneficial' effects of starvation ketosis which included appetite suppression and an almost total reliance on bodyfat and ketones to fuel the body. It is still used to treat severe obesity but must be medically supervised (13).

At this time, other researchers were suggesting 'low-carbohydrate' diets as a treatment for obesity based on the simple fact that individuals tended to eat less calories (and hence lose weight/fat) when carbohydrates were restricted to 50 grams per day or less (14,15). There was much debate as to whether ketogenic diets caused weight loss through some peculiarity of metabolism, as suggested by early studies, or simply because people ate less.

[...]



"Somewhat difficult to understand is why ketogenic diets have been readily accepted as medical treatment for certain conditions but are so equally decried when mentioned for fat loss. Most of the criticisms of ketogenic diets for fat loss revolve around the purported negative health effects (i.e. kidney damage) or misconceptions about ketogenic metabolism (i.e. ketones are made out of protein).

This begs the question of why a diet presumed so dangerous for fat loss is being used clinically without problem. Pediatric epilepsy patients are routinely kept in deep ketosis for periods up to 3 years, and occasionally longer, with few ill effects (3,5). Yet the mention of a brief stint on a ketogenic diet for fat loss and many people will comment about kidney and liver damage, ketoacidosis, muscle loss, etc. If these side effects occurred due to a ketogenic diet, we would expect to see them in epileptic children.

It's arguable that possible negative effects of a ketogenic diet are more than outweighed by the beneficial effects of treating a disease or that children adapt to a ketogenic diet differently than adults. Even then, most of the side effects attributed to ketogenic diets for fat loss are not seen when the diet is used clinically. The side effects in epileptic children are few in number and easily treated, as addressed in chapter 7."

No comments: