I think I have tried everything on the market for stopping my 4 yr old Shih Tzu from eating her own poop.  It started when she was about 1 year old.  I try to make sure I am with her when she goes to the bathroom, and remove the "temptation".  

Any ideas? 

that's strange just make it sure that everytime that your dog poop, you'll clean that right away so that your dog will not eat it.. 

Yeah that's strange...Some dogs eat poop but I think not every time it poop...That's a first time I heard about that...

A lot of dogs do this, its nothing to worry about and it isn't a sign of bad nutrition. Its just what puppies do, same as babies put things in their mouths there not supposed too. They normally grow out of it between the age of 1-2.
A good way to stop them is by clearing up the poo asap,
Also if you put a small amount of fresh pineapple in its food it wont be tempted to pick up the poo, don't know why this works, but it does.

 I own an Akita and he did this like twice when he was like three months old. I tried to clean up after each as soon as he did to resist the temptation. Also I had to practice some reinforcement, like very time he poop and he went near it I would shout 'No" and call him, then he would come and i would "pat" him for not eating it. I had to do this a few things and now he doesn't eat his poo. I am not sure it it's natural or not but I really didn't like the idea of him doing it but It seems quite a few puppies do it so I guess they eventually grow out of it...

I have a 9 month old Maltese that started doing the same thing.  I did research upon research to see why our precious one could eat such nasty (EWWW just the thought of it) when we feed him so well, but I couldn't find anything.  So my husband & I got to thinking what would deter him away from wanting to eat that nasty.  "JABANERO SAUCE" we went outside with him in our back yard and when he went poop we would put Jabby Sauce on it and boy when he would get a whiff of that Jabby Sauce,  he didn't even think about putting that poopy in his mouth.  Now in the morning when he gets up he goes outside and goes pee and poop, then comes inside and gets a treat.  No more poopy eating,  don't have to use the Jabby Sauce, and I only give him the one treat in the morning.