Do you eat before or after you exercise?

Depends: on what your goals are. If your weight is fine and your looking for optimizing your performance for work-outs, it's possible you'll eat before(usually a light snack) and after. If your goal is exercising as part of a weight reduction plan, You're probably best off just focusing on eating after your work out.

Depends: Really depends on the goal of exercise. In general it is a good idea to eat a 200-300 calorie snack 1-2 hours before exercising so that you can have energy to get the most out of your exercise routine. After exercise it is important to eat some protein and carbohydrates to aid recovery. Many find this counterintuitive, but you really do need to fuel your body to get the most out of your workouts!

I'd say after.: For cardio, exercising in the AM before breakfast will burn fat stores for energy rather than just using calories from food you've eaten. For weights, eating a healthy mixed meal afterwards helps replenish the carbohydrate stores and deposit protein into the muscles for building.