embiggen vs fatten up

embiggen

verb
  • To enlarge; to make bigger. 

  • To enlarge or grow; to become bigger. 

fatten up

verb
  • To make bigger; to expand. 

  • To cause to gain weight by means of feeding. 

  • To become fat or fatter by gaining weight. 

How often have the words embiggen and fatten up occurred in a corpus of books? (source: Google Ngram Viewer )