My take on food, having recently walked from Almeria to Ourense. A walk of some distance covering a range of physical and weather environments, and also differing "cultures" of bars and food which adds to the uncertainty of what is ahead.
At home I usually have my take on intermittent fasting but this had to be adapted to a Camino
I started with a policy of not carrying any food - just water often with electrolytes. I have often done this on other more modest walks, and also on my last extended bike ride of 2 months when I would ride for 80 +/- kms before eating (noting riding at a reasonable speed is more energy demanding than most walking days).
My intention was to start the day with 2 coffees and usually a tostada y jamon (or croissant if fresh). This of course needed to be adapted to where the bars were and if they were open before I started (usually around dawn or 30 minutes earlier), and some days coffee wasn't available for an hour or 3, and on some days not at all before I finished walking for the day (usually 5 or 6 hours) when I usually had my major meal during lunch time, with a focus on getting protein.
[side note: if your order carne con salsa sin frites sin huevo occasionally you get a large plate of carne
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I never ate late at Spanish dinner time - around 6 I would have a light meal usually something from a "supermarket".
I adjusted my no-carry-food policy on about 3 days (out of 65 or so). I packed food on 3 extreme days which were longer and when there was no food enroute and I was likely to arrive too late for lunch and a low possibility of buying food later (eg Sundays).
That turned out to work well for me. Hunger or lack or energy was not a problem. The walk included quite a bit of climbing, for example in the stretch before Granada some days climbing up to look at the snow capped Sierra Nevada close by. Later along the Sanabres with more climbing on many days.
I went without eating for 24 hours from memory, on three 20 - 25 km days when the expected bars or shops did not exist, or their food was not to my dietary constraints or liking. Then walked the next day after a light breakfast.
On balance it worked out pretty well. A form of intermittent fasting and not carrying food was eminently practical for me and presumably can be for some other people.