One of the primary effects of caffeine on metabolism may be its ability to speed it up. Studies have indicated that caffeine can cause a 10-percent increase in the metabolism of the average person, although it may work faster on women than it does on men. Many people attempt to lose weight because of the effects of caffeine on metabolism, but are usually not successful with the use of caffeine alone. Caffeine may boost metabolism and make a person feel more energetic overall, but there are some additional side effects that may be considered undesirable.
Another benefit of caffeine on metabolism levels is that the boost in energy might make it possible for someone to work out longer than he or she normally would. Working out can contribute to weight loss when done without caffeine, but in many cases a person might not have the energy or desire to get started. Caffeine can sometimes make a person want to exercise, because it might be hard to sit still for long periods of time with caffeine in the system. Athletes often drink liquids containing caffeine just before a game or training session in an effort to increase their endurance levels.
The effect of caffeine on metabolism might be negated by some of the more unpleasant side effects. A person who drinks more than six cups of coffee or other drinks containing caffeine throughout a given day might begin feeling jittery, nervous, and irritable. He also may find that he is unable to sleep at night, which will likely result in a reduced energy level the next morning that might persist throughout the day. After a person has consumed more than 10 grams of caffeine in a day's time, she might start to experience serious side effects, such as a drastic spike in heart rate and blood pressure.
If a person truly wants to take advantage of the effects of caffeine on metabolism, he can go about it in a safe way. When caffeine is used for weight loss purposes, it may be best to have it just before working out. If caffeine is going to be consumed in the form of coffee, it may be a good idea not to sweeten it up with too much sugar or milk, as this could counteract the weight loss effect. It might be best to use artificial sweeteners in place of real sugar if a person wants sweet-tasting coffee. Additionally, it is usually never a good idea to have too much caffeine at once, and spacing it out throughout the day might be beneficial to a person's health.