mslucy - there was a programme on tv a few months back about an experiment they did on blokes with low sperm count, they changed their diet, basically a lot more healthy food. In 3 months they had all dramatically improved on their little swimmers.
It took as over a year to conceive dd, not that long I know compared to other people, but we are both super healthy, so we couldn't understand it. I was very lucky that my dh eats well anyway, although I did nag him about booze a LOT, sounds very similar to your dh's habits. drinks a fair bit at home, any excuse, and goes way OTT on nights out.
Anyway, I'm wittering on. The best foods to get DH to eat are...
obvioulsy eat fruit and veg and cut down on processed food, but the best things I read about to help sperm count was SEEDS (how ironic!)
Pumpkin seeds, sunflower seeds, and if dh won't eat them, then nuts, but not peanuts, brazil nuts, almonds, etc.
I believe you can buy zinc and selenium supplements too. It's zinc that the nuts are full of that help 'libido'.
God, I sound like Gillian McKeith.