Man is composed of two parts: a mortal body, and an immortal spirit. The Lord calls our body a 'tabernacle' or a 'temple' since it is the temporary residence of our eternal spirit. Since the spirit and the body together are the soul of man, what affects one affects the other. By taking care of our bodies we make our "tabernacles" an acceptable house for our spirits. By defiling our bodies with drugs, tobacco, or unwholesome foods it affects our spirits adversely.
Our bodies are a gift from our loving Heavenly Father. He has given us the opportunity to come to earth and receive our bodies because He wants us to become like him! God has a body of flesh and bone, we were created after His image. When we came to this earth our spirits (created by our Heavenly Parents) and our bodies (created by our earthy parents) united for our mortal experience. Our bodies are an important tool for learning and growth. As we care for them properly we will be ready to learn the lessons our Father has prepared for us. As well as be physically able to act on the promptings that we can receive from His Holy Spirit. In order to hear promptings from our Heavenly Father through the Holy Ghost we must be clean and pure. His Spirit cannot dwell in unholy places. However as we keep ourselves worthy the Spirit of the Lord can truly dwell within us! This is what the scriptures mean when the prophets teach that our bodies are Temples. Our bodies house our spirits and they also have the potential to receive the Holy Ghost!
Our bodies are gifts from God. We are given these bodies during this life as we try to become more like God. Our bodies house our spirits. Therefore we need to take care of them! Just like any other gift we receive, we should care for our bodies so that we can use them to their fullest. We believe that we should eat good, wholesome things that will help our bodies to be healthy. Not only does this help us to feel better physically, but it also helps us to feel better spiritually! A temple is a place where the spirit of God can dwell, and our bodies are also a place where His spirit can dwell. Just as we feel better living in our homes when they are clean and taken care of, our spirit can better live in a clean, taken care of body. When we take care of ourselves we are more alert and active. We can enjoy doing more things. We show respect for God's gift as we take care of it and receive many blessings for that! As we take care of our bodies we can better feel the spirit, or God's presence in our lives.