The Word of Wisdom was revealed to the Prophet Joseph Smith. It is a law of health that teaches us what foods we should and should not use to keep our bodies healthy. We know that it was blessing to receive a phsyical body when we came to earth.
The reason why it is a blessing is because we need a physical body to become like our Heavenly Father. Our bodies are so important that the Lord calls them temples of God (Corinthians 3:16-17). Like my friend Mike has always told me, part of our reason for being on earth was to learn to control our bodies as well. I believe this means controlling your appetite as well as other physical wants and pleasures.
Things not to put into our bodies
Before baptism, we are told to abstain from: tobacco, alcohol, tea, and coffee. During our investigation of the church, our missionaries often told us that these things would keep us from being receptive to the spirit and I believe this makes sense.
This that are good for our bodies
Grain, wheat, fruits, vegetables, and wholesome herbs are good for us. We should use them with wisdom and thanksgiving.
Fish is good for us. The flesh of birds and animals (chicken, pork, beef) is also provided for our food. However, we should eat meat sparingly.
Blessings from Obedience
Doctrine and Covenants chapter 89 also states:
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. (D&C 89:18-20)
I have personally seen the blessings of being obedient to the word of wisdom and in an odd way, I am glad that it is a law of health commanded by Heavenly Father. This definitely makes weight loss a no-brainer. Why would we not want to obey and please our Father in Heaven?
You can read the short chapter of Doctrine and Covenants Section 89 by following this link: