Lord Hutton, conducting an inquiry into the death of David Kelly, a British intelligence analyst, wanted to know if an evaluation of Iraq's threat had been exaggerated (in the American vernacular, hyped). The Times correspondent reported that a UK Ministry of Defence official, Brian Jones, told the inquiry that some scientists had "worried that the authors of the dossier were `over-egging certain assessments,' he said, using a British colloquialism for being excessive."
That sent me to the Oxford English Dictionary. "To over-egg the pudding, to argue a point with disproportionate force; to exaggerate."
This metaphor of a dessert enriched with too many eggs is currently used in British politics: "Some of the recent (election) forecasts," reported London's Times in 1976, "may have over-egged his pudding."
The American equivalent of stretching a point is one sense of juiced up, but we are more likely to gild the lily (misquoting Salisbury in Shakespeare's King John: "to gild refined gold, to paint the lily"). I cannot think of a common US metaphor for throwing a perfume on the violet or making a tale taller, which goes to show that you can indeed teach a visiting pundit to suck eggs.
The hot phrase among headline writers in Britain this summer was sexed up. The BBC's Andrew Gilligan quoted a source later revealed to be David Kelly as saying an intelligence report was "transformed ... to make it sexier." This was then transformed into sexed up.
The 1942 American Thesaurus of Slang defined sex it up as "to introduce sex into, as a story." Britain's Observer in 1958 wrote, "The business of 'sexing up' the titles of foreign films is a trick well known in both France and Britain."
Tom Wicker in a 1964 book review noted that Henry Adams' Democracy was a novel "that might go pretty well in paperback today if they sexed up the title." And Tom Wolfe titled a Life magazine article The Sexed-Up, Doped-Up, Hedonistic Heave of the Boom-Boom `70s.
The phrase has nothing to do with copulation. Its predecessors were spiced up, or "given added piquancy;" and tarted up, or "dressed flashily and provocatively."
"While sexy can be good," Jan Freeman astutely noted in The Boston Globe, "sexed up suggests fakery."