Digital Gee

Before today's 26 miler in 84 degrees (with 14 mph winds), I weighed myself. During the ride, I ate one breakfast bar, drank 12 ounces of water and purchased and drank 32 ounces of delicious, ice cold orange juice. I felt fine throughout the ride.

When I got home, I weighed in and I'd "lost" 1.5 pounds. Does this mean I didn't eat/drink enough for the ride? After weighing in, I drank another 24 ounces of orange juice and a while later a large glass of ice tea, and I feel (and felt) fine. I'm sure I've "gained" back all the weight.

But should I have eaten or drank more on the ride, given the temps? I thought I'd heard that if you weigh the same before and after, you've hydrated/eaten properly.