There’s food for picky eaters.. I know Royal Canin has one called ‘Special’ for little dogs off the top of my head… Or add some wet food to the dry..
Ive had two puppies that LOVED Cheerios. Its helped them develop a little more muscle and just get overall healthier combined with regular walks or runs.
Unfortunately Royal Canin is mostly grains and fillers, little meat. Not the worst food ever, but not something I would feed my dogs. I’ve never heard of feeding Cheerios.