, 'If you put in more calories than you burn off, you put on weight'. SIMPLE.
Quite. Straightforward mathematics.
On the stand up front, that reminds me of Jimmy Carr:
Carr is coming to end of a rant about lazy tubsters, when a woman stands up in the audience..
Heckler; "You're being ignorant. Some people have glandular problems."
Carr: "Glandular problems? Do you have glandular problems? What are you taking for that? Pies?"