Nowadays, more and more food establishments are asking their clients beforehand if they have any dietary restrictions, food allergies or intolerances, and Spain is no exception.  However, it is always best to be on the safe side when it comes to food allergies or intolerances and to communicate them clearly beforehand to your server. Here is a clear way to do so when ordering: Perdone, soy alérgica / alérgico a… (Excuse me, I am allergic to…) and fill in the blanks. Perdone, soy intolerante a… (Excuse me, I am intolerant to…) and fill in the blanks. Here is a list in Spanish of the most common food allergens: Frutos secos (nuts, in general) Nueces (walnuts) Marisco (seafood) Crustáceos (crustaceans) Cacahuetes (peanuts) Huevos (eggs) Leche (milk) Soja (soy) Gluten (gluten) Lactosa (lactose) Sésamo (sesame) Pescado (fish)