Has anyone made a daily tracker?

I would like the members on my website have an online diary/tracker of sorts. In simple terms it is a table with a row for each day - eg, enter what they ate for breakfast, lunch and dinner each day. This should be visible to the member themselves of course, and also the admin so that they can add suggestions/comments. Does someone have an idea of how I can implement this? Are there any existing features that I can use?