A change in food certainly wouldn't hurt but look at the treats you are feeding and how frequently you are feeding them. If you feed quality kibble but really bad treats you could have a problem.
Three meals a day at this point. Ideally breakfast should be fed about an hour before you go to work or, if you don't work, half an hour or an hour after you are up and moving in the morning. (My pup gets breakfast around 9:00, 9:30.) Lunch should be around lunchtime - between 12 and 1 or so. Dinner usually around 5:00 or 6:00. Don't get yourself stuck in a routine where you feed at exactly the same time every day. And don't worry if something comes up and you miss a meal. I know it sounds bad - but life happens and will continue to happen for the next 10 to 15 years. You do not want to be that person who has to leave Christmas dinner with family because your dog will get sick or tear up the house if his food bowl doesn't hit the floor at 5:10.