Here's why:
* "Mental and physical health" is more specific and emphasizes the two distinct aspects of well-being.
* "Health" is a broader term that encompasses both mental and physical well-being. It acknowledges that these two aspects are interconnected and influence each other.
The best choice depends on the context:
* Use "mental and physical health" when you want to specifically highlight both aspects, such as in a discussion about the importance of addressing both physical and mental health concerns.
* Use "health" when you want to use a general term for overall well-being, such as in a sentence about the importance of maintaining good health.
Ultimately, both phrases are correct and convey the same meaning. Choose the one that best suits your purpose.