puppy fat

puppy fat (uncountable)

1. (informal) The natural fat on the body of a child that normally disappears at adolescence.
   • 1972, Georgette Heyer, Lady Of Quality, London: The Bodley Head, page 87:

     "I was not pudding-faced!" "Oh, believe me, you were! You hadn't lost your puppy-fat."

• baby fat