"Milk, often considered nearly perfect food, contains fat, sugar, and protein."“Milk, often considered nearly perfect food, contains fatness, sweet, and protein.”
I would like to add “a” to food --> a food.
I don't know if it is correct?
"Milk, often considered near perfect, contains ..." But I think it would be better to leave the 'food'
Also, you probably would want to say "fat" instead of "fatness" because "fatness" is the state of being fat.