Katy, I think it varies for every kind of meat. As a very rough guide I think you could say 100g of raw chicken breast would be approximately equivalent to 75g of cooked chicken breast.I don't think it's an exact science here & it was hard to find much info about it. As you know Cohen's weight's are raw weights. If they were cooked weights you would be eating roughly an extra 1/4 of what is stipulated on the program and guessing weights is not good. Best in future, if you can organise it, to have them weighed out & in the freezer & stress to your LH that you need to be fairly strict if this is to work properly. I didn't like doing this with my LH as I didn't want to put him off cooking for me but he understood why & took it well & was then very careful. Cheers, Cate.