Both sites come across as being very well put together and are visually pleasing. I purposely just flicked around instead of reading the content to see what I instinctively clicked rather than be lead around and found the sites easy to navigate.

If I had to nit pick...and I do...here are my hair splitting, personal opinion, subjective blah blah blah:
Reversing Diabetes - the Facebook icon doesn't match the look of the site. There are plenty of FB icons that would match with the round company logo and the 'Top Of Page' link. I even think Xara has one in the Content Catalogue.
RD - the drop down menu under About Us needs to be sternly stared at. It's an obvious Xara Navbar from the early 2K era and doesn't match anything else on the site.
RD - on the Causes Of Diabetes you have a social media bar on the left. It either needs repeating on all pages or removing. It looks odd just being on one page.

Wrought Iron - on the Products page I would like to see the sub menu bar on the main page as it appears on the individual product pages. My reaction was to click the photos to make them bigger, not as a link. I then used the sub menu bar to hop to your other products. Going back to the main Products page had me wondering where the sub menu bar had gone to. Not a huge deal as it only took a split second to work it out, but it's worth mentioning.
WI - On the Design page you have a totally different heading format to the other pages.

Both sites - really, really subjective here. The body text font...slightly too big??? This is like saying 'how hot do you want you curry', very much personal taste.

Sorry I can't help out with the blog side of your question, but I have seen references to Nabble in an iframe on several occasions here on TG.