In one research source, много was described as an adjective with a number of examples. But it was also described as a noun, where, as here, there is specific noun attached to it.
I don't think that is correct, and it's simply a matter of it still being an adverb, but with an unstated noun attached, here "of food".
If it were a real noun, it could possibly be declined, and that doesn't seem to be the case - много is never declined - or is it?
I just came here with same question. Wiktionary says it's an adverb, but some of the words that it translates mnogo with are not adverbs!
much: ok, also an adverb
a lot of: can be an adverb, but can also be a noun
many: a determiner
very: an adjective
I'm wondering now if our confusion stems from the English language, rather than the Russian...
It's not declined like a noun would be, but there are a comparative (бо́лее ) and a superlative form as for an adjective.
Also, it's followed by a noun that takes the genitive, sing. for non-countable nouns and plu. for countable nouns (мно́го examples here: https://en.openrussian.org/ru/%D0%BC%D0%BD%D0%BE%D0%B3%D0%BE). Correct me if I'm wrong, but I don't think that adverbs/adj. normally trigger a particular case in a subsequent noun. Seems more like the behaviour of a preposition or a verb.
In the US also, although usually it has a noun attached and slurs the following article: "lots of beans" becomes "lotsa beans" or "lots of artichokes" becomes "lotsov artichose"
When by itself, it's used usually as a kind of emphatic answer: "Does he eat a lot of meat?" "Oh my, yes - lots and lots."
Actually lots is the informal way of saying a lot, so it is correct to use it. http://www.oxfordlearnersdictionaries.com/definition/english/lot_3
"Lots" slang for "a lot of", so it's not ok to use it. (At least "lotsa still retained the grammatical meaning, even if tge pronunciation was slurred). That's what I would have concluded, but it just goes to show how, in some matters, there's no right or wrong in language, just a matter of opinion.
Using lots instead of a lot sounds more slang to me, I am a native from the US; In grade school we would always be reminded that a lot =2 words, so it certainly was correct to use. 'Lots' just sounds slightly vulgar -like someone shoving (shoveling) food down their throats, I advise some discretion in its use plus I used to teach English -might be a bit picky. Of course in England they probably say it in a higher tone as if they were gathering heather while they were saying it or daffydowndillys and the like!