Guide to Civic Leadership Blogging (2005 U.K. edition)
"Media diet" refers the range of content one regularly consumes from a variety of media: newspapers, magazines, newsletters, TV and radio shows, websites and weblogs, etc. As a civic leader, you can select items from your media diet and blog those you think your readers might find interesting.
In the not-too-distant past, many leaders would photocopy important articles and hand them to colleagues and staff members. More recently, emailing the text of the article or the link to it is more common.
But blogging the media item (and linking to it, of course) and then adding your own commentary on it gives it additional "shelf life" and makes it seem less like email spam. The link encourages your readers to deepen/widen their understanding about an issue… and as a public official, one thing you want to encourage is a more involved, more informed citizenry. Also, the author/publisher of the original piece will likely appreciate the link, and it encourages the search engine spiders to keep returning to your blog.
If your media diet includes other bloggers, it’s acceptable to attach a comment to their post. But it's generally more interesting (and there's more of an incentive) to write in your own blog about what you read and then link to the blog post that you're writing about. That's how the blogosphere works. It helps widen your audience, as you'll likely get others doing the same to your blog, thereby steering readers to you.