You cannot turn off the feeds for your blog.
Your feeds are created automatically unless you mark your blog as private. The content of password-protected posts will not display in your blog’s feed.
You can send only a summary of your posts:
For each article in a feed you can select Full text or Summary. Full text means that the entire contents of a post are included in the feed. Summary means that only the first 55 words are included in the feed, along with the option to continue reading the rest of the post.
Which option to use is a matter of some debate. Visit Problogger’s view for some more information. This setting also affects what users receive in their email subscriptions.