You have heard of fat-free drinks, but what about one that has negative calories?

It is called "Celsius", the metabolism boosting, calorie burning soda.

Celsius has vitamins C and B, green tea and ginger, no carbs and 200 milligrams of caffeine.

That is about the equivalent of two cups of coffee.

The company that makes the drink says it will make you lose weight.

But some registered dieticians are concerned.

Dietitian Lona Sandon said, "If your coupling or having this beverage along with a few diet sodas with caffeine or along with your coffee in the morning you could be getting too much caffeine and harming your health that way."

Celsius is not the answer to dieting.

The drink's manufacturer says it is best used with a combination of exercise and a healthy diet.

Celcius comes in a variety of flavors including: cola, ginger ale, lemon-lime, orange, and berry.