Chapter 3:
Blood-Sugar Control
Why control blood-sugar levels? Because keeping blood sugar within the proper range-versus allowing it to rise too high or drop too low-will dramatically enhance both fat burning and appetite control. Whenever blood sugar rises too high or falls too low, the body is signaled to stop burning fat. In the "too high" scenario, fat-burning stops because you have all that sugar in your system-so the body decides to either burn or store the incoming sugar and save its stored fat for later use. In the "too low" scenario, the body stops burning fat because it lacks enough glucose to "prime" your metabolic fat-burning engine (certain breakdown products from carbohydrate metabolism are needed to get fat metabolism going and keep it going). In addition, this "too low" scenario sets off alarm bells in the brain (which relies on glucose as its primary fuel source), and the brain responds with its own set of signals that increase your appetite-especially for more carbohydrates.
Low-Carb Versus Low-Fat: What to Eat?
Although scientific studies show us that low-fat/high-carbohydrate diets can certainly help you lose weight, they can be difficult to follow because of the problems associated with selecting the "right" kinds of carbohydrates at every single meal. When you eat the "wrong" type of carbohydrate-rich meal, your insulin and blood sugar levels spike and then quickly drop, which can make you crave even more carbohydrates soon after eating. High blood-sugar levels and chronically high insulin levels can also lead to increased fat storage and reduced rates of fat breakdown (more on that topic appears in the following section).
At the other end of the spectrum, many of the popular low-carbohydrate diets do a decent job of taking care of the blood sugar-control aspects of weight-loss metabolism, but they can also elevate cortisol levels-so the overall effect for most people is rapid weight loss (during the first few weeks of the diet), followed by a plateau, and then by a slow weight regain over a period of several months. Indeed, two very recent studies, published in The New England Journal of Medicine in 2003, showed that although early weight loss (during the first three months) on a low-carbohydrate diet is greater than on a low-fat diet, total weight loss after one year was comparable between the two dietary approaches. Similar studies of very-low-fat Hawaiian diets and moderate-fat Mediterranean diets have shown similar magnitudes of weight loss and duration of weight maintenance.
by Shawn M Talbott, PhD