You cannot delete your account yourself, and there’s no info on how to have it done manually either, so try this:
Contact them using the contact form found here: http://www.foodnetwork.com/contact-us/package/index.html
Briefly explain that you would like to cancel your account. Include your account details (username, email address you used for signing up).
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.