Rather than using corn or canola oil, I'd use coconut or cocosoya oil. I've noticed GREAT improvement with it. Not only weight wise, but coat, skin, and hoof quality as well. Started with 6oz a day and have now reduced to 4oz. I'll have to look again to check ingredients for sugars, but Missing Link is also really good for healthy fats. Flax, rice bran, etc. I love Missing Link. I do also suggest probiotics. Fastrack is great but expensive. Manna Pro makes a probiotic that works well, too. Check with your vet before starting them, though. Good luck!