Not sure if this will help, but, I used to find I would stay at a steady weight or gain a few pounds when I was training for a century (100 miles, not metric). I would be very hungry after the ride so I'd eat a lot, and then would be so tired for several days afterwards that I had no energy for any exercise. I'm much better off doing more moderate efforts and doing them consistently.

I still do a few long rides each year but no longer than 60-70 miles, and most weekends during warm months I keep it to 30-45 miles (2-3 hours or so). That way I'm still able to exercise during the week and my appetite doesn't get as messed up by burning 4000+ calories in one day. During the winter I exercise indoors so I keep it to about an hour per session.