Lab eating behavior

Question
We have had our male chocolate lab for a little less than a year now.  Within the last few months he has started to eat his own feces.  We keep the yard picked up but if he can find any he is chewing/eating it. We feed him twice a day, 2 cups in the AM and 2 cups in the PM and he get alot of exercise.  Are we not feeding him enough?  What causes this behavior?

Answer
Just why is poorly understood.  Picking up the yard is the best control.  You can try food additives, pineapple juice, canned pumpkin, Forbid, or Deter.

Likely you are feeding him plenty.  Your dog definitely should be narrower at the waist than the hips and chest.
You should be able to easily feel the ribs, but not see them.  Each dog is
different.  Standard recommendations are a good place to start, but each dog
must have its food adjusted to its individual needs. Here is a link to a good illustrated guide,
http://www.longliveyourdog.com/twoplus/RateYourDog.aspx