The fact that he's overweight should not be an issue in him running for president. That said, it will be. This country will never elect a fat man to the oval office in this day an age. People will claim they're concerned for his health, and how well he'll be able to do his job, but discrimination against the obese is the last kind of socially acceptable discrimination.
Obviously his weight makes him a target, but Chris Christie's weight is his own problem. There are far more pressing and relevant issues that ought to be in the spotlight. How Chris Christie chooses to live his life is his own business. Last I checked, it wasn't immoral to like McDonalds.
This is a pretty superficial and silly thing to be focused on. The guy is a powerful politician and a potential contender for the 2016 presidential elections, and all people can talk about is the fact that he is overweight? This should not be a front line issue. Let's focus on what he stands for and what kind of policies he wants to enact.
Chris Christie is a politician. He is not a health food advocate or a fitness instructor or a fashion model. His job is to help run a state and provide for the people of his state. What should matter when it comes to Christie are his leadership skills, his ideals, and his policies.