How can my friends see my journal entry
 

Under the privacy settings I selected friends only for all of the options. But the journal entry where I typed my notes is not showing up. How do I make this available for my friends to read?

Your Diary will not show up no matter what privacy settings you choose.

As far as I can tell, the other settings can be made public/private so that people can view your statistics and then can help you with your weight loss/fitness goals.

When you think about it, a personal Diary really won't help in this regard. Plus it would be unmoderated comments so this in itself presents problems.