The "Charlie's Angels" star was rumoured to be penning a guide which would help impressionable young girls stay fit and healthy, and now bosses at HarperCollins have confirmed that the book will hit shelves in 2013, reported Daily Star.
Diaz's book will offer advice to young women about nutrition and general well-being and she hopes the as-yet-untitled manual will "engage and empower" females.
News of the 39-year-old's writing deal comes just months after she announced plans to launch her own well-being organisation.