Caffeine is a naturally-occurring substance found in the leaves, seeds or fruits of over 63 plant species worldwide and is part of a group of compounds known as methylxanthines. The most commonly known sources of caffeine are coffee and cocoa beans, cola nuts and tea leaves. Caffeine is a pharmacologically active substance and, depending on the dose, can be a mild central nervous system stimulant. Caffeine does not accumulate in the body and is normally excreted within several hours of consumption. In larger amounts, it can cause nervousness, anxiety, sleeplessness, and is used medicinally as a diuretic and headache remedy.
Calorie is the standard unit for energy measurement in nutrition.
Equal to one kilocalorie or 1,000 calories. They connect the arterial and venous systems. Sources of CHO include vegetables, fruit, rice, bread, pasta and whole grains. 1 gm CHO yields 4 kilocalories of energy. They vary from simple sugars containing from three to seven carbon atoms to very complex polymers.