help me with my dog

Question
okay i have had a golden reteriver well i have 2 but i onl have problems with the one she is not old she is prolbley 4or 5 we have had her since she was a puppy and she is really over weight we love her so much we feed them 1cup of dry dog food in the morning and evening she probley weighs over 100 pounds her hips are really bad she wobbles to walk because she is so overweight i dont know how to help her but want to have her forver please help!

Answer
2 cups of food shouldn't benough to cause such a problem.  I would carefully check to see if she is managing to find something else to eat?  Could anybody in the family be sneaking her food?  Is she getting lots of treats?  Could a well meaning neighbor be giving her table scraps?