"The Summer I Lost It" is a sweet gem of a novel, with a funny, optimistic protagonist and a strong message that I think will resonate with middle grade readers. It's not often that you see this kind of novel in middle grade/YA fiction, and considering that childhood obesity is a contemporary issue of mounting concern, it was refreshing to see Kath's approach to it. She's done her research well, not only crafting the struggle of a young woman who wants to lose the weight, but also touching base with things that a girl her age would care about, like the influence of her friends and Kat getting her first boyfriend. There are also helpful recipes and tips included in the novel to punctuate the message that those who may struggle with their weight at an early age can be active, and lose weight in a responsible way. None of the messages feel overbearing or instructive, but rather light and easy to understand.One concern I saw raised was whether or not the novel oversimplifies the process of losing weight - I don't think so, personally. The fact that Kat goes through a formal training program and diet moderation for her respective age is realistic and noted well. It doesn't focus on just one dimension of losing weight, but rather encourages being physically active as well as modifying one's diet, with the added notation that junk food isn't off limits, but portion control is important. For the audience that it's oriented towards, it's very appropriate and the presentation won't feel overwhelming to the reader. The only concern I had reading this at first was that Kat herself seemed maybe one or two years younger than I thought her purported age would be, but as the novel went along, her concerns as a 14-year-old girl felt more palpable, and it was cute to see her relationships and confidence growing. Probably with not as much conflict as I expected the novel would have (because there are times when young teens/young adults struggle with this even more than the protagonist in this novel), but I think considering the message coming across and the intention being to inspire, this is a great novel to jump to, and a quick read at that.I would definitely recommend "The Summer I Lost It" to its target audience. It was an influential read.Overall score: 4/5Note: I received this as an ARC from NetGalley and Stone Arch Books.