I used to stop, but as has been said it is pointless because you quickly give up on the book that way.

Then I remembered that when I was reading as a child I would regularly not understand A LOT of words; that did not bother me at all. Now that I am an adult, and tend to understand all of the words that I encounter in English, I feel that I ought to also understand all of the words that I encounter in French. 

In other words when I was a child I did not have the expectation of understanding every word, and so I persevered with reading and now rarely see a word that I do not know. This took years of reading English: so it will take years of reading French. 

One more thing: I think that my former obsession with particular words shows a misguided 'philosophy' of language. Language is made up of collections of phrases. It is important to understand phrases and this is possible without understanding every single word. When our mothers said to us as babies: 'my dearest, you look hungry, I have some delicious bananas for you', we did not worry about what she was suggesting with 'dearest': we smiled because we knew that it was dinner time. (The phrase means something apart from the 'meaning' of any of the difficult words here) The 'meaning' of the individual words became clear after years of winding examples, and they became vivid that way. But the phrase is not essentially about any of them.

No,

I do that if I see the same word repeating several times or if I really need its meaning to understand the message. 

I would be wasting my time looking up for a word like that on a dictionary, a word a see now and forget it from the moment I finish the book.

Hi Moa
I highly recommend you continue this way.

I recommend the following method to my students:

1st reading: read the whole text (or part - you could break it down into chapters or pages). Aim to understand the whole thing. If you can guess words from context that's good, but don't worry about it too much.

2nd reading - stop when you come across things you don't understand. Work out the meaning or look it up.

3rd reading - read it again without stopping. This time, it's for enjoyment. Hopefully you'll understand more than the first two times!!

Good luck

Kathryn

I am with Wanda on this.  Having a Kindle makes it so easy to learn new words (just click the cursor on the word and the definition is there) and there are so many books available for the Kindle, that I do not like to read in my target language without it.  My Kindle is one of the most important language learning tools I have. 

I like to highlight the words that I realize I have looked up more than once and later put them in my Anki program to memorize with spaced repetition.  Reading on the Kindle works somewhat like a space repetition program anyway because the more common words keep coming up and I keep looking up the definition to remind myself until I know them.