I Forgot the Name of That ___! discussion

So, this book is a young adult fiction that was published possibly 4 years ago. The main character is a boy who had a twin, a couple of younger siblings, a mom, and a crazy dad with a lot of money. The dad builds an underground bunker, then says that a disaster is coming and locks them all in this underground bunker. The twin brother is stuck in the "dystopian wasteland" above, and the mom begins to breed babies for eating later (yikes!). Eventually the boy finds out that this is all an experiment by his crazy father, they all go above ground where he is restablished with his twin, etc. The name is on the tip of my tongue...but it's been like that for two weeks and I'm no closer to remembering the title.