GOWRI SHANKAR

Many people skip breakfast believing that it's a good way to lose weight. Then half way through the morning they begin to feel haggard and are ready to drop. They run for a quick fix of energy - a chocolate bar, soda, or even worse, one of the new energy drinks that are full of caffeine and sugar. And indeed, it gives them a jolt, but it is relatively short-lived. By lunch time they're exhausted again, and ravenously hungry. No one wants a roller-coaster morning like this, and besides, it's a sure way to overeat and gain weight. But it can be avoided by eating the right foods. These foods give you a steady stream of energy that will make you feel great throughout the day. GLUCOSE The energy you need to get through the day comes from the conversion of the food you eat into glucose and the uptake of this glucose by the cells of your body. Food comes in three forms: carbohydrates, fat and protein. For the most part, our energy comes from carbohydrates (or at least it should). Unfortunately, carbohydrates have got a bad rap lately, and people have been told to avoid them as much as possible. The problem with this is that it applies to only one type of carbohydrate, and carbohydrates come in two varieties: complex and simple. Complex carbohydrates consist of long molecular chains that release their energy slowly to your body. Simple carbohydrates, on the other hand, consist of short molecules that release their energy quickly. Simple carbohydrates require little breakdown and their energy goes almost directly to the bloodstream, so they are fast-acting. As a result they should be avoided as much as possible. If your body runs short on energy from carbohydrates, it does, indeed, turn to fat and protein. Both can be broken down into glucose, but the process is more complicated (compared to carbohydrates) and it produces several undesirable byproducts. Protein is not "clean burning" as carbohydrates are; they produce ammonia and urea as byproducts. The breakdown of fat to glucose is also very complicated. Furthermore, some types of fat are unhealthy. Nevertheless, both protein and fat are important in our body. We will concentrate mostly on the breakdown of carbohydrates to glucose. And we'll start with the speed at which it is turned into glucose and fed to your bloodstream. How it is sustained in your bloodstream, and how well it is taken up by your cells and converted to energy is also important, but we'll leave that to later. A measure of how long it takes after we eat a certain food for its glucose to hit our bloodstream has been around for a several years; it's called the glycemic index (GI). The higher this number, the quicker glucose is actuated. The scale is set up with glucose itself having a GI of 100; on this scale GI's of over 70 are high, and under 55 they are low. This is helpful because we don't want to eat foods that are converted to glucose very rapidly and used up quickly. But there is a problem. GI only takes into account the carbohydrate in a food, and most foods have other things such as fiber, water, fat and so on in them. As a result, carrots (with only 7% carbohydrates in them) have a relatively high GI of 47, and watermelon (which is mostly water) has a GI of 72. To get around this, another measure is now used: it is called the glycemic load (GL). It is obtained from GI using the formula: GL = GI/100 × carbohydrate content of food (minus fiber). The guidelines for this scale are: GL's under 10 are low and desirable; GL's over 20 are high.