This should be done moderately. We are all aware of the potential dangers of caffeine - including anxiety and insomnia. The caffeine in coffee can speed up the body metabolism. This is also known as nutritional enhancer in some cases.
This makes a lot more sense since caffeine is widely known as a stimulant. Recent studies show that it can help you burn more calories than normal, maybe up to 10 percent more. To be on the safer side, it is best limit your intake to a single cup in the morning and one in the afternoon. You may add a skim milk to it and try adding no sugar, some people prefer it that way.