What to do if your child has behavior problems

So your son or daughter is a nice enough kid, but acts out. A lot. (Or just a bit, but at the wrong times)
How do you fix it?

First, as I've mentioned before, the key to good behavior is summed up with three simple things:
1. Good diet
2. Plenty of exercise
3. Proper discipline (establishing and maintaining good boundaries)

So, as with any endeavor, if we want to achieve certain goals, we must do known tasks to get there. Since we know there are only three things that keep a child from proper behavior, the only logical thing to do is systematically provide each of the three until the problem is solved.

I've written on Discipline already:
Set boundaries Stick to them. It really is that easy.
 How do you know if discipline is what your child needs?
If you have ever said this: "If only my son/daughter would do that," then your child needs discipline.

So, let's get to diet and exercise:

Diet is pretty easy. 

You are the parent. Provide healthy food.
If it is bought off a value menu, it is not healthy.
If it could have been plucked from a garden, and eaten as it sits in front of you now with no more help than a knife could provide, then this is a great snack food. I'm talking fruits, vegetables, and nuts. (but be mindful of nut allergies).

Fruits and vegetables are "any time" foods - always allowed.
Meats are best grilled or baked. Fried meat is OK sometimes. Breaded and fried is not OK... ever.
Grains are generally good. Be sure your child does not have a grain allergy - wheat / gluten allergies are most common.
If you don't have time... MAKE time. It can be done. Decide you want to do it, and quit making excuses.

To be avoided:
Artificial additives (colors, flavors, preservatives).
Yellow #5 is known to have the most common and most severe effects.
Caffeine. Seriously, people.
Sugar - particularly processed sugar sources.

If you have set good boundaries, and still get whacked-out behavior, eliminate Yellow #5 first.
If you still have issues, eliminate wheat (gluten allergy or perhaps a yeast allergy).
These two are presuming you have eliminated sugar and caffeine from the diet.


Exercise:
This is even easier. An hour of play every day. Outside is best. 
Running, jumping, and generally moving a lot are all recommended activities.