You may want to use upper case L in "Diets, Weight
loss"
Nice work, I'm still in two minds about tags and genres
At present I have a Genre column which is well sorted, and has limited entries.
For Tags I tend to want more info.
For example I would have a book with the Genre Science-Fiction and the tag would have extra info like space opera, Aliens, Culture, Dystopian, Future, etc
Not really sure on the best approach