To add to the general commentary...
I only have an hour of aerobatics, but I learned a lot, starting with the food thing. After the first 1/2 hour (which was a raffle prize), I told the CFI I wanted to pay for another 1/2 hour, but I wanted to take a break first. The positive gees were the only problem-
at the bottom of every loop (pulling about three Gs) it felt like everything in my torso was going below my belt, and I got a little clammy and green-looking. didn't fell light-headed, but it was very unpleasant.
He asked what I'd had for breakfast, and I told him the truth: two cups of coffee, some toast, and about three cigarettes.
I had been worried about puking, so I'd intentionally showed up hungry.
This is bad for acclimation to g-loading, and for some people, bad for acclimating to inverted flight or any of the rest of it. He advised me to always eat "a big ol' greezy breakfast" (his exact words) before an aerobatic flight... not
right before, obviously, but it's a good idea to get the body working nominally with plenty of fuel. Coffee or any stimulant/diuretic is a bad idea, as it will dry you out and boost your heart rate to begin with, and of course smoking, with its effect on blood oxygenation and adrenaline production, is a no-no, even though smokers feel "soothed" by cigarettes.
I'm sure some aerobatic pilots who do it often can get away with abusing their bodies or flying on an empty stomach, but for any beginner it's a really bad idea. And when you look at real champion aerobatic performers, you see athletes, with athletes' health habits (for the most part).
Anyway, I had some cookies or something and some juice and water while we briefed for the second half, and felt much better on the next flight. FWIW, in the Zlin 242 with its bubble canopy, he taught me to look first at a wingtip during the loop entry, then overhead coming over the top to keep it straight. We did all of the loops over a long straight stretch of railroad tracks.
