Hola Mary
In this sentence
Claudia siempre le añade mucha sal a la comida.
Claudia always adds a lot of salt to food.
this "le" refers to "to it/to the food"
With pronoun le as an indirect object pronoun it is quite common to find it in this type of sentences where the indirect object (a la comida) is mentioned in the sentence. It is a repetition of an indirect object.
In English though there is no translation for it.
We could also omit it and say:
Claudia siempre añade mucha sal a la comida.
Claudia always adds a lot of salt to food.
There is a more advanced lesson on repetition of indirect object pronouns, where you can see more sentences like this one.
Have a look:
Repetition of indirect object pronouns with verbs
I hope this helps
Saludos
Inma
