Google-gaggling, haven't found the lryics. Found references to the song here and there, e.g., Click here
re a Ladies Barbershop Quartet singing it, with this fragment printed,

Somewhere overweight people
Just like me
Should have someplace where folks don't count every calorie.

Later in the song, they sing:

If bluebirds ate as much as I
There'd be some big fat bluebirds in the sky.

(hee hee I love it...dimly remember hearing it m'self, I think)

If it's any help, there's a book "Steve Allen's Songs: 100 Lyrics with Commentary". For its Blurb on the official Steve Allen website, Click here