I have tried to be consistent with the amount of food I feed my dog. He is very active but some days more active then others. The other day he was so active he didn't even want to eat and just slept. I do provided treats while we walk and other times throughout the day as rewards for good behavior. The food I give him provides a chart as to how much to feed him based on calories burned. I put an activity monitor on my dog (http://Voyce.com) for a few months and found his caloric burn to be pretty consistent on average (about 1200 Cal/day).