He said that that sounded a little strange...
As Ingmar already wrote this is because the vocabulary used (während) is wrong — not because of the grammar.
Not knowing the intended meaning of this sentence it is only possible to guess which word is correct. Let's assume mit is correct …
Ich habe mit gutem, nährendem Essen überlebt.
According to the German grammar this is correct.
The comma in this case replaces the word und so you list multiple adjectives that describe the word Essen. You might also say:
Ich habe mit heißem, nahrhaftem, teurem Essen überlebt.
Because this is a list of adjectives of the same type all of them must have the same ending (-m) one single adjective would have.
You leave out the comma if replacing the comma by und would change the meaning of the sentence however the endings of the adjectives (-m) should be the same anyway.
A second possibility would be an adverb that describes another adjective: This means the word gut describs the word nahrhaft and not the word Essen. (In English you would use the word well instead of good in this case):
Ich habe mit gut nährendem Essen überlebt.
The adverb is placed in front of the adjective and the adjective has the same ending (-m) it would have without adverb.
Ich habe mit gutem nährenden Essen überlebt.
I must admit that many native speakers would say this. However I don’t think it is correct.