Remember, during the start of the story we're told that Mr and Mrs Lewis received a strange package that had a written note stating that they should expect a man by 8 pm. That Man later turned out be Mr Steward who further provided them with information about the package.
Meaning that "when you eat food, your fat burns out slow and gets stored, and you try to work out to get rid of all that excess fat. You try really hard but nothing works
