The formation of fat and the glycemic index

The glycemic index helps explain the dynamics of weight gain and loss very well. Although it is not likely that this is the complete reason in all people why weight is gained in the face of substantial calorie restriction, it would appear to be a primary factor. But before going into what this index is and why it is vital in the management of one's diet, let's look first at how fat is formed, and how fat can later be broken down.

Insulin plays a major role in the storage of all the breakdown products of food that are absorbed into the bloodstream. Glucose (carbohydrates), triglycerides (fats), and amino acids (proteins) are all pushed into storage forms in the cells of the body by insulin. Obese people generally have higher insulin levels than people who are not obese, and any food they eat is more likely to proceed directly into storage as fat in the presence of this increased amount of insulin. This is one reason why obese people can eat very little and still not lose (or possibly even gain) weight.Since the level of circulating insulin in the body is so important in causing food to become fat rather than to be directly utilized for energy, it is vital to understand what directly stimulates or suppresses the amounts of insulin released from the pancreas (the organ that forms and stores insulin). When glucose is released into the bloodstream from the digestion of food, insulin is immediately released to help metabolize that sugar. However, and this is crucial, the faster glucose is dumped into the bloodstream, the more insulin is released. The SAME total amount of glucose released more slowly over a longer time will result in much LESS of a total insulin release from the pancreas. Therefore, a "spike" of glucose released into the bloodstream effectively overstimulates the pancreas, resulting in an over-release of insulin for the actual amount of glucose absorbed. This mismatch of too much insulin for too little glucose has predictable and consistent negative effects on the body.What does too rapid an insulin release do to the body? First, much of the rapidly released glucose that caused the increased insulin release will end up being directly stored as fat. And since this phenomenon is related more to the rate of glucose release than to the total amount of glucose being released, glucose can be stored as fat even when the total calorie count of the food is severely restricted! Any diet that restricts calories but still regularly allows for a sugary dessert as a portion of those calories totally misses this important point. If you want to lose weight, you must choose the right food and digest it properly. Delightfully, as we shall see, feeling hungry all of the time is not required in this weight loss process.Also important in understanding this interplay of glucose and insulin is the fact that glucose, and not other forms of sugar, is the major stimulus for insulin secretion. Fructose, the major sugar in most fruits, has much less of an effect on the release of insulin. Fructose will affect glucose levels only after it undergoes a transformation process in the liver. Therefore, fructose cannot directly cause a spiking of glucose into the bloodstream from the gut with a corresponding over-release of insulin. However, when the levels of glucose are already high, both fructose and amino acids can help to stimulate the further release of significant amounts of insulin.