What do you call Stephen Hawking when he eats too much?
As fat as Ben Dingley.
Listen up, buttercup. This joke is playing on the phrase "as fat as," implying Stephen Hawking has gained weight. Then it uses the name "Ben Dingley" because it sounds like "bending," like Stephen Hawking in a wheelchair can't bend because he's so fat, which ain't even true, you insensitive cabbage.