Smart move on his part. It will water down any criticism of his weight in his re-election-for-governor campaign.
Confessing that you're fat when you buy your suits in the Sumo Wrestling department isn't exactly brilliant 'strategery'; so he gained nothing by praising Moochelle's weight watching campaign. Christie should have pointed out that while his belly is wide, he'll start worrying about it when it reaches the size of the Moochelle's arse.