I find that eating in any quantity rarely goes well with cycling, and that's doubly bad when it's hot. Little and often is the order of the day, which is something I've learned through experience. What I did get wrong was drinking too much in one go when the thirst kicked in on the first day, with inevitable digestive consequences.
As for the achilles thing - not a clue. I'm going to chalk it up to bad luck, perhaps related to heat, or to so much group riding on the flat (I've done prolonged tours before, but solo or in groups of disparate speed where I've ridden at my own pace and regrouped at the top of each climb), or perhaps due to insufficiently worn-in shoes. I'm taking things easy and avoiding walking/cycling/crouching/etc for a few days and seeing how it goes.
While the various surfaces encountered on this tour have certainly explained a thing or two about the design decisions that went into my sturdy German touring bicycle, I remain intrigued as to what those setts are like when you're riding a Dutch bike with traditional semi-flat tyres, and indeed why the diagonal pattern is quite so much worse vibration-wise than the square ones.
