Beyond the walls of the McVitie's factory, there have been other subtle changes in the confectionery world. The Mars bar and the KitKat have both gone through redesigns in a bid to boost sales. And sales certainly need to climb if Britain wants to be the fattest in the international family of nations. We may be miles ahead of the rest of Europe, but we must increase our obesity rate by an imposing 23 per cent if we're serious about catching up with America.