Current last paragraph:
Feeds include the subject (when present), the full text of the entry, and a link to the entry. However, Atom specifications require that every item have a title. If an entry does not have a subject and the Atom feed is requested, the username and date/time of posting are included as the title element.
By default, feeds include the subject (when present), the full text of the entry, and a link to the entry. In Atom feeds, since Atom specifications require that every item have a title, an entry with no subject will include the username and date/time of posting as the title element.
While it is not possible to disable your journal's feeds completely, you can restrict the feed output to the entry subject only or the entry subject and the entry body content up to the first line break. To do either one, go to the Admin Console while logged in and type:
set synlevel level
Replace level with title to use only the entry subject or summary to use part of the entry text. To reset the feed to display the entries' entire contents, replace level with full.
Or something. Since the can't disable, synlevel stuff goes along with the talk on what feeds include, I wanted to de-emphasize the Atom feed stuff by changing the however.