Which one is what? IS required to be more healthy? The body, or the mind?
Both! If your body is unhealthy, then the mind will be as well. All the vitamins, minerals protiens etc. that the body needs, so does your brain. If your body is lacking the proper nutrients, then it also lacks the essential amino acids that the brain needs to make and maintain the chemistry (neurotransmitters) levels it requires. It also won't be able to manufacture the non-essential amino acids (neurotransmitters), all of which are needed to regulate every function of the mind and body, how you feel pain, how thoughts are processed, moods, etc.
Yes,the mind is located in the body thus it is part of the body.