Dr. Sears:
Q: Your pals Drs. Michael and Mary Eades insist that the brain does not need carbs to function, that the body can produce all the glucose it needs from the protein/fat one eats. It is so frustrating to have all the experts making contradictory statements. Could you please explain? Also, are you saying with regard to low-carb, it's not about the weight loss as much as about silent inflammation? For example, I know several people who have lost a lot of weight on an Atkins-type diet and have kept it off for years, but perhaps the silent inflammation still rages within?
Please advise, thanks, Angelina
Dear Angelina,
A: The primary fuel source for the brain is glucose. If there is not enough carbohydrate in the diet, the body will recognize this as a significant stressor and release the hormone cortisol to counteract it. The increased cortisol will generate the necessary glucose from either protein or fats in a process known as gluconeogenesis in the liver. The longer the extreme carbohydrate restriction goes on, the more cortisol is generated, often resulting in increased insulin resistance and the regain of any lost weight. Obviously, not everyone is genetically the same. This is why some people will do very well on an Atkins-like diet (as long as their intake of arachidonic acid is low). However, clinical studies indicate that after 12 months most people have regained much of not all of their lost weight probably due to the resulting increase in silent inflammation.