A human body has many faculties, the most important are mind and intelligence. How we use them makes all the difference to what we will achieve or lose.
What do we normally do? We pit our faculties one against another. Judge for yourself. The mind is normally inclined to think negatively. What does such thinking do? It affects the health of the body. What does the intelligence normally do? Rather than telling the mind to stop the mind's foolish ways, it participates in the minds lusty plans, by proving justification for the same, even though these hurt in the long run. The body is not far behind. It craves for lusty enjoyments.
Is this not surprising? Aren't all the faculties God has provided us meant to cooperate and help one another in order to enhance their cumulative welfare? They should, but normally don't. If we wish to avoid such a situation, we need to follow God's instructions, as given in the Bhagavad-Geeta. This is real intelligence and not the one that justifies mind's foolish plans. The body should be maintained the best way possible. Only then miseries resulting from bodily pains will reduce. The bodily lusty demands should be curbed by superior spiritual intelligence. A healthy body helps the mind in being peaceful.
Therefore, a spiritually intelligent person strengthens the mind by doing many spiritual practices like developing God consciousness, becoming God's devotee, doing sacrifices for God and offering obeisances to Him. Then, the health of the mind is ensured. Giving more importance to the body is unwise.
The body’s health cannot always be ensured, but the mind, can always be kept healthy. We can do so by fixing the mind on God. Thus, we ensure minds health, but also avoid many diseases which are results of faulty thinking. I try to chant incessantly when negative thoughts appear in my mind, preventing my mind from thinking negatively.