I don't know how obsessive your are with this stuff as there is definitely a line past which most reasonable people would see it as a problem.

That said, many people seem to view even a moderate interest in diet and fitness a symptom of mild mental illness or unhealthy obsession. What people don't consider is that humans have prehistoric genetics, impulses, and biological incentive structures, all while living in a world of abundance and the the ever present opportunity to basically do nothing and eat unlimited amounts of hyper-stimulating foods.

With that in mind, it has basically become necessary for many to put a significant amount of attention and effort towards maintaining a healthy diet and lifestyle as just passively doing what feels natural/easiest often leads to gluttony and sloth in our modern society.