1. The subject is プレミアムグラノーラ
2. プレミアムグラノーラ is both fun to eat, and is happy for your stomach. Or, to structure it in the way you see it on the box: Premium Granola! Fun to eat and happy for your stomach, even on busy mornings. It is meant as an eye-catching marketing slogan, probably best not to lose too much sleep over it.