One of my dogs is nearly 11 and a diabetic. I inject her twice a day usually around 6.30 am to 7.30 and then 12 hours later. I inject as she is feeding because she is a flighty little madam and if she knows I have a syringe in my hand she clears off even though she is blind. I also give the injection site a little rub after injection. My vet wasn't too concerned about before or after food, he just said that if she doesn't eat up to 2 hours after the injection she would be OK because her appetite should kick in, just look out for signs of a hypo......never had one yet touch wood, I have found that a large hide chew is a good treat because it keeps her teeth clean. I buy them from Pets at home in a pack of two they look like rolled up paper also a little bit of carrot, apple melon or cucumber acts as a treat.