If I bought a pricey sports car, I would be motivated to take good care of it, polishing it to a radiant shine and keeping the engine in tiptop working order. But of far greater value is the sacred human body, designed and created by God. “And God said, Let us make man in our image, after our likeness. . .So God created man in his own image, in the image of God created he him, male and female created he them” (Genesis 1:26-27). God has given us a principle and a promise to care for and maintain our bodies. These principles of health, referred to as the Word of Wisdom, can be read in full by following this link: https://www.lds.org/scriptures/dc-testament/dc/89?lang=eng
The Lord provides a promise to those who comply with these principles: “And all saints who remember to keep and do these sayings, walking in obedience to the commandments, shall receive health in their navel and marrow to their bones; And shall find wisdom and great treasures of knowledge, even hidden treasures; And shall run and not be weary, and shall walk and not faint. And I, the Lord, give unto them a promise, that the destroying angel shall pass by them, as the children of Israel, and not slay them” (D&C 89: 18-21).