[Tomasz Klimkiewicz]

It is absolutely correct to use 'a lot' with uncountable nouns (such as 'food', the example you quoted). It is very common to say or write 'a lot of time' 'a lot of money' etc. The expression 'a lot of' often occurs in its plural form, 'lots of', but that does not alter the rules of its application.

Hope this helps.

Regards,
Tee Kay

Edit: the example sentences 'A lot of food are eaten' and 'There are a lot of milk' are incorrect, BTW, 'are' should be replaced with 'is' in order to make them correct. Basically 'a lot' means 'very much' OR 'very many' and does not modify the grammatical number of the noun it refers to. Thus 'a lot of money IS needed for the project', but 'a lot of children ARE absent from school today'.