It would have been published around 2012.
It's about a guy taking a girl with him to parallel universes. The universes are empty/dangerous because there is an evil presence there; something like big black winged animals (that smell foul).
The villain is using that force to take over this universe, and eventually becomes the foul-smelling 'bird'.
The one thing I remember specifically about the book was that when they jumped universes, they had to eat a ton of calories. I think he ate multiple orders of pancakes in a restaurant the first time he was explaining to the girl that they had to go.
