Sometimes when I play football (soccer) I get incredibly light headed similar to when I'm really hungry.
What is the best type of food I should eat before playing a team exercise, preferably something that won't feel heavy.
Eating carbohydrates (sugars and complex carbs, not fibers) will prevent you from getting light-headed, weak, or tired during exercise. Often a single piece of candy or a cookie is enough to restore and maintain energy. Play around and determine the amount that works best for you, but don't take more than you need or you'll lose the weight-loss/maintenance benefits of the exercise.