My three now will eat anything and everything put infront of them - food or not. If we tell them to eat it, they will
This makes pill giving EASY peasy, but can be a pain in the butt for the obvious reasons.
Our old guy however, pickiest eater, EVER. He hated most foods - but loved treats. He'd eat his kibble if we treated it as treats and made him do tricks for it
. However, we did just let him eat when he wanted to. With him we had the luxury of free feeding, so we just left his food down. It'd go untouched for a day or two, then all of a sudden he'd just eat it all, rinse repeat. He'd get picker as we got down to the bottom of a bag (stale, maybe?). He never got too skinny though. He never let himself get to that point, until he got older and started to get sick. Then we did all sorts of tricks to get him to eat (hiding cat food in the bottom, feeding his whole 4 cups by hand, drizzling juice from tuna on it, etc) - but his lack of appetite wasn't due to his being picky at that point, it was his illnesses.