I feel the best available format for a log book is as demonstrated below*:
This log book page is reproduced with the kind permission of
NovoNordisk. To see a pdf version of a complete log book from their
web site click
here.
* That is, with the exception of the layout that is available in my new
book:
Diabetes for Canadians for Dummies. (How's that for a shameless
plug?!)
