I have always just kept my dogs bowls full and never had a problem except once. I have found that if dogs know that the food is there anytime they want they don't overeat. The exercise level of my current shorthair varies drastically between hunting season and off season. He still stays they same weight. In fact the only weight problem he has is keeping enough weight on when hunting three days a week.

Our old lab had to be fixed due to a prostate problem. He balloned up after the operation. We started restricting food to bring his weight down. We had to restrct both dogs because they both had access to the food. Because my shorthair was unsure when food would be available again he started eating more than he normally would even though we were measuring How much he was "supposed" to need. He started gaining weight too. We finally went back to keeping their bowl full and both slimmed down and stabilized again.