First of all, I just want to say that I love health. Nutritious food, strenuous exercise, and a daily dose of fresh air? I'm all about it. And living a disease- free life? Who doesn't wish this for them and their loved ones. And of course mental health: mental clarity and optimism are obviously very important in order to live a happy life. I love that our prophets and apostles offer advice on both Physical and Mental health, because both so important for our well- being, and often seem to be overlooked in religious settings.
The state of our health affects every facet of our life—our feeling of personal well-being, our approach to work, our social interactions—even our service to the Lord." Barbara B. Smith, "Good Health- A Key to Joyous Living", Conference October 1978
Among the most familiar of the health scriptures is the eighty-ninth section of the Doctrine and Covenants, wherein the Lord specifies both substances that are for our use and those which are detrimental to us...Scientific research has verified the harmful effects of tea, coffee, tobacco, and alcohol—even upon the development of an unborn child." Barbara B. Smith, "Good Health- A Key to Joyous Living", Conference October 1978
“Nutritious meals, regular exercise, and appropriate sleep are necessary for a strong body, just as consistent scripture study and prayer strengthen the mind and spirit” (Thomas S. Monson,“That We May Touch Heaven,” Ensign, Nov. 1990, 46).
“The condition of the physical body can affect the spirit. That’s why the Lord gave us the Word of Wisdom. He also said that we should retire to our beds early and arise early (see D&C 88:124), that we should not run faster than we have strength (see D&C 10:4), and that we should use moderation in all good things. … Food can affect the mind, and deficiencies of certain elements in the body can promote mental depression. … Rest and physical exercise are essential, and a walk in the fresh air can refresh the spirit. Wholesome recreation is part of our religion, and a change of pace is necessary, and even its anticipation can lift the spirit” (Ezra Taft Benson, "Do Not Despair," Ensign, Nov. 1974, 66).
"Because our Heavenly Father wants us to take care of our bodies, He revealed essential information on how to do so. Much of this information is found in Doctrine and Covenants 89 and is known as the Word of Wisdom". "The Lord has Given us a Law of Health", Liahona February 2012
"We should also avoid anything that is harmful to our bodies, such as overeating or refusing to eat enough healthy foods to maintain our health.""The Lord has Given a Law of Health", Liahona February
"Your body really is the instrument of your mind and the foundation of your character." Boyd K. Packer, "Ye are the Temple of God", Conference October 2000
"As I was running I began to notice something that, frankly, troubled me. Time and again I was being passed by men who smoked, drank, and did all manner of things that were contrary to the gospel and, in particular, to the Word of Wisdom.
I remember thinking, “Wait a minute! Aren’t I supposed to be able to run and not be weary?” But I was weary, and I was overtaken by people who were definitely not following the Word of Wisdom. I confess, it troubled me at the time. I asked myself, was the promise true or was it not?
The answer didn’t come immediately. But eventually I learned that God’s promises are not always fulfilled as quickly as or in the way we might hope; they come according to His timing and in His ways. Years later I could see clear evidence of the temporal blessings that come to those who obey the Word of Wisdom—in addition to the spiritual blessings that come immediately from obedience to any of God’s laws. Looking back, I know for sure that the promises of the Lord, if perhaps not always swift, are always certain." Dieter F. Uchtdorf, "Continue in Patience", Conference April 2010
"In our search to obtain relief from the stresses of life, may we earnestly seek ways to simplify our lives." L. Tom Perry, "Let him do it with Simplicity", Conference October 2008

