Risks of eating 900 calories a day?

I've been eating about 900 calories a day for about a year now.
I'm 15, 5'8, about 120 pounds.
I'm not low of energy or anything...I've gone through cross country season (3-5 miles a day) eating this way.
I eat fruits and vegetables, and I get protein and my vitamins everyday. Just, obviously not as much as others.
I'm a healthy eater in other regards; I don't eat any junk food or fast food.
And I drink tons of green tea (if that accounts for anything).

So can anyone tell me what I'm at risk for?
Any answers are much appreciated, just not rude ones, please. :D
Assuming that you are not loosing weight, the only concern would be a vitamin deficiency... Meaning, just make sure you take a multi-vitamin and you are covered..

Also, one other thing you might want to consider is making sure you get enough calcium. This will help reduce your risk of osteoporosis later in the future... A simple glass of low fat milk per day should be enough...

In short, if you are not loosing weight and still getting some exercise, then there really is not much health concern to doing this...


Good Luck and I Hope this Helps...
Fat gain in the future would be a strong possibility as your body might get used to 900 a day,carbs are the enemy.