You only feed your dog once a day? May I ask who recommended you do this? I've always been told this is a no-no. Perhaps you should check with your vet regarding his eating only once a day, unlses your vet recommended this feeding schedule. I just find it very odd.

I have always fed my dogs once a day..They still get the amount they need..Most people do feed once a day...they aren't humans

I don't think there's anything wrong with once a day feeding in adult dogs. I will comment that just because a dog is overweight doesn't necessarily mean the food is not good. The cause for dogs to be overweight is that they are not getting enough activity and are taking in more then they are burning just like what happens to us. Dogs are animals that hunt and travel for hours in wild. Either feed less of what your feeding or get him more active. OR even better do both and adjust each as necessary. Read the ingredients and find their actual definitions for pedigree and I'm sure you will cringe.