I really don't know the answer to this one. I know that in women, weight and sudden gain/loss can change ovulation habits but, I've never heard that for men and sperm production.
I looked it up in TCOYF and didn't find anything about weight and sperm count either. If you have the book, pg 170-176 address issues which may cause low sperm count. (tobacco, steriods, ulcer meds, jacuzzis, etc.)
I hope someone will have the answer for you!
Zachary James, 7/22/03-7/27/03, born at 26wks - severe pe
Praying for a miracle... TTC #2 is a go!
Southern California Coordinator