1.  I am a vegetarian (I'll eat fish but no red meat) and that is hard for people to understand here.  Meat is a staple food here and even if people say they understand that you're a vegetarian, they still think you'll eat ham because that's not considered a 'meat' here and it's been difficult getting food I'll eat.
2.  I was very frustrated, but trying to be nice I would just go along with it and I even had to eat ham a couple of times.
3.  The past 2 weeks I've been getting food I like, no ham etc.  My host mom know what I like to eat and what I don't and is very accommodating.
4.  I realized one day when I was very frustrated with my meal situation that nothing would change unless I did something about it.  So, little by little I would tell my host mom, "no, I don't like that food" or if she served me something, I would leave behind the parts I didn't eat.  She would the realize that I really meant what I said and now my meals are great.
5.  I realized that in order to be hospitable and accommodating, Spaniards with shower you with food, but I had to find my assertiveness to say no sometimes and often repeatedly and stand by my position to make myself clear.  It was scary because I didn't want to offend anyone, but in the end it makes everyone happier because I'm happier and they're happier because of that.
6.  I think in many intercultural interactions, it is good to go along with customs and say yes, but in some personal areas like eating meat etc, assertiveness needs to happen.  I feel more confident now and I know if another similar difficult situation arises where my values are different that the host culture, I feel confident in asserting myself and it will produce a more positive outcome.