If your fish are bloating, it is more likely to be from bacteria in the stomach creating gas than the expansion of the pellets. Unfortunately, very often goldfish cannot efficiently digest many of the land based proteins used in their food. Feeding less at a time is definitely a good move, but you also need to ensure that your fish have enough fiber in their diets to push these things through as well. Are you seeing bubbles in their poo? What kind of food are you feeding, and what are the tank conditions, size, parameters, inhabitants, etc...