Hi Jill
My wife has a wheat and dairy intolerance and does her best to avoid most wheat and dairy based products when we travel in Europe. This said we did the
Camino Frances route in Spain back in 2007, the Via Francigena in Italy in 2008, and my wife walked the Jakobweg in Switzerland in 2010 by herself and we are about to walk the Chemin du Puy in France this May and June.
Like yourself, she loads up on fresh fruit and nuts throughout the day and this is actually less expensive that purchasing prepared meals in many of the cafes and restaurants. For extra carbs, she orders rice and potato based meals, hearty salads especially made with tuna and eggs, or hearty soups made with lentils and beans. Knowing a bit of Spanish to ask the right questions also helps. Overall she has managed to get by and this rarely means we are spending more for food than anybody else. We have been to Europe together approx a dozen times during the last 10-15 years too. Oddly the toughest place for her is probably the UK, not Spain, Italy or elsewhere.
This said, oddly for her she can tolerate more wheat and dairy based products while in Europe than at home here in Canada. We think is much to do with the way food is processed here as compared to places like Spain and Italy. We also believe that since she is more active (walking 20-25 km plus each day helps), she can digest complex breads, pasta and cheese products better than when she is back home.
Finally I think a budget of 20-40 euro per day, is just fine especially for Spain which is much cheaper than Ireland, Depending on what you are prepared to walk each day but 33 days to reach Santiago from say Saint Jean PdP should be fine too but some people longer and others less time.
Trust this helps
Neville
http://www.verderamedia.com