I don't know what it is, but I always have to force myself to eat a cliff bar or what not. I drink plenty when it's hot, but I never have an appetite. I did this route last monday
http://www.mapmyride.com/routes/view/6780880 Which is an annual memorial day group ride, and probably one of the toughest courses I've ever ridden. It's only 81 miles, but that's close enough to a century.
I admittedly walked the hurricane mountain part, which was the catagory two climb around the fifth mile. I tried climbing it, and was having trouble keeping my weight foward on the bike to keep my front wheel on the ground, and my bars are raised slightly, so it felt like my hands were up to my chest given the 20% grade in spots. After biking up a short way, I decided to walk the rest and save my legs.
The descent down the back was about the scariest ride I've ever taken. You had to ride the brakes the whole way. The road was so insanely narrow, and had cars coming up. Thick woods on both sides, steep and unpredicatable corners. It seemed like I couldn't grip the brakes tight enough, and when you hit a bump or frost heave, you automatically let go of the brakes so you can grip the bars so you don't fall. So your bike instantly accelerates 15mph before you can get back on the brakes. It was a two mile ride down.
From there we tried catching up to the group, my friend and I. And both ended up bonking around the 20 mile marker lol. The whole group met at the top of Pinkham Notch, which was the second major climb. Even though I was bonking, I trucked up the climb without any major issues. All 70 of us had lunch, and left shortly after. I only ate half a protein plus bar. I recovered very well and was very strong from there on. I rotated to the front of a group to take a pull, and ended up dropping the group. That was around the mile 40 or so. Then I annihilated the last major climb which was a long gradual catagory five. I ate three bananas from the support vehicle at the top even though I wasn't hungry at all.
What does all this mean? I even did a 140 mile ride last year and awsn't hungry at all, and forced myself to eat. Is it just something I probably won't have to worry about?