What is your budget for food? I fed diamond for awhile and with all the recalls i just couldn't, so we now sac a little of our going out to eat money so I can feed my dog Acana. (I also saw you have several dogs) There are several decent kibbles out there that are "budget friendly" now something to consider with higher quality kibbles, diamond bags recommended that I feed my dog about 3 1/4 cups of food in one day, acana little over 2 cups.
If whatever kibble u decide, if he looks like he getting fat, just cut it back a little, do less treats, no table scraps...
Build a flirt pole, swimming, heavy hand walking, running, spring pole, fetch, tug o war, anything you can do to make the dog move will to some degree exercise him.
Spreading the truth one minor post at a time or trying to learn what the truth is.