I'll never forget my college roommate. No matter how much he ate or how much he drank he never gained any weight. His response was always the same, "I have a fast metabolism."

So what is metabolism? If it is a fast metabolism that keeps an overeating, over drinking, non-active college freshman without any weight loss problems then is there something the rest of us can do to speed up our own metabolism? What is it the rest of us need to know about metabolism that can help us achieve our weight loss goals?

The metabolic rate is simply the rate at which you use up energy as in calories. The higher the metabolic rate the more calories you burn, the better the weight loss. The lower you metabolic rate the fewer calories you burn, the slower your weight loss. Your metabolic rate can depend on a number of different factors and many people are quite surprised at what can actually speed up your metabolism.

For example, most people trying to lose weight are often surprised to learn that eating less can sometimes slow down your metabolism and therefore slow down the amount of weight loss. Most weight loss experts agree that when you eat very small amounts of calories, the body "thinks" that there is not enough food available and will slow down your metabolism in an attempt to conserve energy.

Therefore, it is possible, that eating too little can actually slow down your weight loss.

This weight loss theory is fairly simple to follow. When the body does not have enough calories it will do everything it can to conserve the best stores of energy that it has. This means that it is possible that the body will, instead of using up the reserves of fat and making you thinner, actually start to burn the muscle tissue so that it can maintain a reserve of fat.

One possible way to make sure that this does not happen is to make sure that you are eating enough food to keep your body from believing that it should go into starvation mode while, at the same time, control your caloric intake so that you will achieve the weight loss that you desire.

There is not an answer that will suit everyone as to how many calories is enough to help with your weight loss. The best way to work out what is best for you is to visit a qualified nutritionist or weight loss expert who will be able to tell you the most appropriate amount of calories for your dietary requirements.

Although your metabolism can slow down when dieting to achieve weight loss, it is believed by many that exercise can speed up your metabolism. This may help in two ways. First, the metabolic rate can be higher when exercising and therefore help to burn off those extra calories. Also, exercising can lead to more muscle which can help burn more calories because muscle burns calories more quickly than fat.

Therefore, while it's true that some people naturally have a fast metabolism, there are things that you can do to speed up your own metabolism that will have a positive effect on weight loss.