You have been given a body of such physical proportions and fitness as to enable your spirit to function through it. … You should cherish this as a great heritage. Guard [it] and protect it. Take nothing into it that shall harm the organs thereof because it is sacred. It is the instrument of your mind and [the] foundation of your character.
Elder Boyd K. Packer, "The Word of Wisdom: The Principle and the Promises", General Conference, April 1996
The above was from a blessing Elder Packer received while in the military in his younger years but it can be used for everyone.
Of course, members of the church have the law, the principle, and commandment, of the Word of Wisdom. This revelation from God specifically calls out certain products as harmful to the body, like tobacco and alcohol, but, included in this principle of good health, is also the "not explicitly" mentioned substances that are still harmful to the body.
This is a "principle with promise".
The word "principle" connotes that there is personal interpretation. They are not specific on what or what is not applicable. Meaning that there is a lot more to the Word of Wisdom than what is spelled out. ANYTHING harmful to the body is not good to consume. Poison, for example, is not spelled out, but is not good for us, as Elder Packer explains. 😊
The point is, we are to take care of our bodies from anything and everything that is harmful to it. It is up to each one of us to listen to the Holy Ghost to determine what that entails and to guide us around it. I find it interesting that part of the blessings promised, as we take caution to our physical bodies, is the wisdom, knowledge, and spiritual rewards we get.
Remember, by small and simple things are great things brought to pass. In other words, by small changes to what we put into our bodies are great results awaiting us.