IF you read not-encrypted feeds (URLs beginning with http:// ) through a news agreggator,
it means that your ISP knows that you somehow read this newspaper or weblog (because of DNS or direct access),
and really knows FOR SURE that you specifically read THIS section of information or category of posts.

But EVEN if you read those feeds via a secure connection (URLs beginning with https:// ),
your ISP still knows which domain names you asked to connect to because of SSL/TLS handshaking (the technical process to initiate an encrypted connection with a given domain name).

So, your ISP knows at least which newspapers you somehow read,
but you may PREVENT it (the I.S.P.) from knowing which sections you prefer, and "HIDE" any page or file you downloaded from this domain name.

=> Ask your favorite newspapers or bloggers to provide an httpS connection to them.
Or subscribe to a VPN provider, and use it with OpenVPN on your computer.