Hunger tells you your body needs more fuel, and eating food replenishes your body's fuel supply. When your body digests food, it converts sugars and starches from carbohydrates into glucose, another name for blood sugar. The glucose enters your bloodstream and travels to individual cells, which then use the glucose as fuel. Any extra glucose is stored in your muscles and liver as glycogen or is converted into fat and stored in adipose tissue.
Carbohydrates
Carbohydrates break down into glucose with the help of various enzymes. How easily the carbohydrates turn into glucose determines whether the carbohydrate is simple or complex. Simple carbohydrates contain only one or two sugars, while complex carbohydrates, also known as starchy carbohydrates, have three or more sugars. Legumes, starchy vegetables and whole-grain breads and cereals are examples of complex carbohydrates that take longer to break down. Vegetables, fruit and milk are simple carbohydrates that easily and quickly change into glucose. Processed and refined foods, such as candy, regular carbonated beverages, syrup and table sugar, also contain simple carbohydrates, but these are "empty" calories and can lead to weight gain. Consuming complex carbohydrates from foods like fruits, vegetables, legumes and whole grains is much healthier, as these do not cause a sudden increase in glucose levels.
Glycemic Index
A foods glycemic index reflects its affect on your blood sugar. The GI scale is from zero to 100, and only foods containing carbohydrates are ranked. A high glycemic index means the food is rapidly digested by the body, causing a spike in blood sugar followed by a steep drop, leading to wide fluctuations in your blood sugar level. When your body experiences sudden fluctuations in blood sugar levels over time, it may develop insulin resistance, which can lead to diabetes. Foods with low glycemic indexes, on the other hand, take a longer time to digest and raise blood sugar more evenly. Low GI foods also stay in your digestive tract longer and help you control your appetite and delay hunger pangs. Keeping your blood sugar balanced reduces your risk of developing insulin resistance and diabetes.
Low, Medium and High GI Foods
The reference foods for determining a food's glycemic index, or GI, are glucose or white bread, both of which have a GI of 100, the American Diabetes Association reports. Foods with a GI of 55 or less are considered low GI foods. Some examples of these are 100 percent stone-ground whole wheat or pumpernickel bread; rolled or steel-cut oatmeal; oat bran; muesli; pasta; converted rice; barley; bulgar; sweet potato; corn; yams; lima or butter beans; peas; legumes and lentils; most fruits; nonstarchy vegetables; and carrots. Medium GI foods range from 56 to 69 and include whole wheat, rye and pita breads; quick oats; brown, wild or basmati rice; and couscous. Any food with a GI of 70 or more is a high GI food. Among these are white bread or bagels; corn flakes; puffed rice; bran flakes; instant oatmeal; short grain white rice; rice pasta; macaroni and cheese from mix; russet potato; pumpkin; pretzels; rice cakes; popcorn; saltine crackers; melons; and pineapple.
Insulin Resistance
Insulin, a hormone, moves glucose from your bloodstream to your cells when your blood sugar level is high. When your body develops insulin resistance, it doesn't respond to insulin as effectively as before, and not as much glucose is moved into your cells. Insulin resistance leads to many health problems, such as Type 2 diabetes, obesity, high blood pressure, stroke and heart disease, among many others.
