@Nanc I have the same issue - not feeling hungry when walking - here my, additional tips:
No matter what, I force a banana down for breakfast, good for calories and minerals.
Watch your water intake, if you are thirsty (even if you don't realise it!) your body will send less hunger signals imo.
Salted nuts are my 'always in a pocket' snack. They keep the water/minerals balance sorted and give you calories via fat.
Instead of elaborated meals, when still walking, try simple, dry bread, I find it easier to stomach when exhausted.
Also good snacks: dried fruit, nuts, olives, chocolate!, banana chips and yes, put some extra sugar in that cafe con leche ;-)
Fast working versus slow working carbs:
If your blood sugar drops too low, you will not feel hungry (but often quite queazy, with a feeling like your stomach is tight shut).
Eat/ingest some fast acting carbs like plain sugar (for example in a beverage) BUT do always follow up with some slow acting carbs like in bread.
Reason being, the sudden sugar increase in your blood will provoke an insulin response and your blood sugar might drop even further. Counteracting that with slow acting carbs will level out your blood sugar level.
Also, if things are really bad, a caldo (broth) which provides you with water, minerals plus easily digestible protein with some bread will set you right very quickly.
Buen Camino, SY