Carbohydrates are the main sources of energy for our body. The end product of carbohydrate metabolism is glucose, which is the main source of energy for your muscle cells and the brain cells. However, not all carbohydrates are created equal. Carbohydrates that are high in fiber, antioxidants, vitamins and minerals are considered as good carbohydrates. Refined carbohydrates which undergo lot of processing and have added sugar are considered as bad carbohydrates.
GOOD CARBOHYDRATES VS BAD CARBOHYDRATES
Is there a difference in a sandwich made from white bread and the one made with whole wheat bread? Yes, for sure. Although both, the white as well as the whole wheat bread are carbohydrates there is a difference in their quality. The brown bread is the good carbohydrate whereas the white bread is the bad carbohydrate.
Good carbohydrates are those that do not raise the blood sugar too high, too quickly. They are found in whole cereals, dals, beans, whole fruits and vegetables that are rich in fiber and are unprocessed. Bad carbohydrates are the highly processed carbohydrate like refined flour, white bread, white rice, white pasta, sugar sweetened beverages, pastries, etc. These tend to raise the blood sugar levels too high, too quick. When you consume too much of bad carbohydrates, they take your blood sugar levels on a roller coaster ride which happens due to the fluctuating high and low blood sugar levels. Too much consumption of bad carbohydrates can lead to diabetes.
WHAT IS GLYCEMIC INDEX?
Glycemic index or GI measures how a carbohydrate containing food raises the blood sugar levels. It is a scale that ranks the carbohydrate containing food based on its effect on blood sugar levels over a period of time normally two hours. Carbohydrate containing foods are compared to glucose or white bread as a reference food which is given a GI score of 100. The foods that we eat can be classified as low, moderate and high glycemic foods:
Low Glycemic Index Foods(GI of less than 55): Steal cut or rolled oats, bran, barley, bulgar, dalia, sweet potato, corn, peas, legumes, lentils, fruits like apples, oranges, kiwi, pears, peaches etc, non-starchy vegetables and carrots
Medium Glycemic Index Foods(GI of 56-69): Whole wheat, rye, quick oats, brown rice, basmati rice, couscous, sweet corn, bananas, raisins, etc.
High Glycemic Index Foods(GI of 70 or more): white bread, corn flakes, puffed rice, instant oats, white rice, white pasta, refined flour, potatoes, pumpkin, etc.
DOES GLYCEMIC INDEX HAVE AN IMPACT ON WEIGHT LOSS?
Currently, there is no consensus that eating low GI foods can help in weight loss in comparison to healthy diets. Some studies do suggest that low glycemic index foods increase the rate of fat utilization and promote satiety ie feeling of fullness for a longer period of time. This can be a helpful tool in losing or helping in maintaining weight. Other studies have reported that a low GI diet does not necessarily lead to long term weight loss. When the total calorie intake was kept the same, diets with low GI foods didn’t lead to greater weight loss than diets with high GI foods.
Any weight loss success by incorporating foods low in GI in the diet may be more due to the fact that these foods are rich in fiber which has a well established correlation with weight loss and weight maintenance. This is how the high GI foods and the low GI foods may have an impact on weight loss:
• Eating high GI foods will make the sugar in them readily available for use. With the sudden surge in blood sugar levels the body produces more insulin to metabolize it. This sudden insulin rush will also deplete the blood glucose levels fast after which the person feels exhausted and shaky. The person will mostly crave a high GI snack which would again be a deterrent in a weight loss.
• In contrast when the low GI foods are consumed, the digestive system processes it slowly thus releasing glucose slowly into the bloodstream keeping the blood sugar levels stable. The insulin too is released slowly which will make the person less hungry and thus eat less.
So, what is the bottom line? At the end of the day weight loss is about burning more calories than what one consumes. This has to be coupled with a physical activity. Selecting foods with low GI will help in better management of blood sugar levels and thus satiety as they are any ways low in fat and minimally processed like whole grains, vegetables, fruits, and low fat dairy products. Given all these considerations a weight loss program that is well designed by a qualified nutritionist can help in long term weight loss.