Vegan Virgin Valentine by Carolyn Mackler takes Mara Valentine through her last year of high school. She's on the fast track to becoming valedictorian until her same-age niece moves in and havoc ensues.
I'm always curious about how eating is portrayed in books. Not eating meat is usually symbolic for someone who is poor, repressed, or showing off. Here Mara's veganism represents her repression and need for control, but it's not her whole life. Luckily, her family is supportive of whatever food choices she makes. There are interesting characters and other fun plots. A quick read.
More books with vegans - Fat Cat by Robin Brande, Uglies by Scott Westerfeld, Scott Pilgrim & the Infinite Sadness (Volume 3) by Brian Lee O'Malley