This is a great idea of how to address our attention to our way of eating, a much needed topic of exploration.
After having done a blog myself, I can give you a few pointers on how to make it successful. First do as much research about the various diets recommended by experts for the various stages of human life as well as for special needs, and when you do a post in your blog, try to give a link or more to indicate your source or for additional reading. Then, reach out to the various forums, as many as you can, to examine the needs of the community as well as to get ideas from them. Try to make your blog a communication piece that brings the community together, and great things will happen with it.