A woman struggling with her sexuality and with an eating disorder finds healing when she falls in love with a fat orthodox Jewish girl. I'll start with what I liked. The prose was snappy and fun. The book's wit burned bright. 

My issues were two fold. First, I felt that the fat character was basically used as a device for the thin main character's healing and not given much agency of her own. Second, growing up Jewish but not orthodox, does not give you the knowledge and understanding of what an orthodox family might look like, behave like, or believe. 

There's an argument toward the end of the book that belied the author's utter lack of knowledge on that front, and there was more than one instance where that clear lack of knowledge exacerbated negative stereotypes. The most egregious example was the argument toward the end of the book where

the main character, Rachel, gets into an argument with Miriam’s orthodox family about Israel. Miriam’s mother is a hardened Zionist parroting surface level talking points, and the argument rises to the point of Rachel getting kicked out. The problem is, the majority of Orthodox sects are anti-Zionist because they believe it’s heretical for a Jewish state to be reestablished before the messiah comes. The whole argument was also so besides the point, with Rachel parroting the most inane overheard on a college campus talking points to Miriam’s mother’s implausible overheard at AIPAC Zionist ones. It had nothing to do with the overarching plot, and it felt like the author trying to remind the reader that while she might be Jewish, and her protagonist might be Jewish, don’t worry, she’s one of the good ones! And this is done in counterweight to this orthodox family, who would be wildly unlikely to hold the positions she’s railing against in the first place. So, misrepresenting Orthodox Jews at a time of rising antisemitism when Orthodox Jews are the most targeted because of their visibility, not great.

So the writing was good. But it gets docked points for offensiveness.