This seems like a stretch, but are you
Milk, especially for babies?
The body of my work
Is growing every day.
Babies grow quickly, and that might be considered the work of their diet
Yet some shell out for phonies;
To that I say "No way!"
Baby formula might be considered fake milk?
I guess I'm somewhat lacking.
Collect me? Waste of time!
Uh, let's pretend I have a good reason for this one...
Undoubtedly this author did by
ending "rhyme rhyme rhyme."
Children's literature does tend to rhyme a lot
Now Available in Original Formula
Formula is a kind of milk-substitute for babies
Title
Two percent is a kind of milk