OECD research conducted by the Programme for International Student Assessment showed reading for fun was the most important indicator of a child's future success.
The fast food chain has only ever offered books with Happy Meals once a year, for several years now, in New Zealand. They successfully trailed the new permanent option last year.
"The response to last year's trial offering the choice of a book or a toy with a Happy Meal was extremely positive. While toys remain a popular option, parents told us they liked having the choice," said Mitchell.
"It seemed like a natural evolution to make books a permanent option with Happy Meals."
There will be two books to choose from with each range of Happy Meal toys, to ensure a wide range of interests are catered for.
The eight books available this year are also gender neutral.
McDonald's came under fire in May when Tokoroa mother Imogene Louise posted on the company's Facebook page complaining about being asked whether the Happy Meal she ordered was for a boy or girl - to determine what toy they would be given.
"Let me tell you something about my daughter. She loves cars. And trucks. And bikes. And skateboards. And pretty much anything with wheels. LOVES them," she wrote.
"Her preferences are in no way correlated with her genitalia. And I bet that almost every child in New Zealand has a like or dislike that does not fit inside those ridiculous boxes society calls gender."
A McDonald's spokesperson said at the time, it was something the company was working on, as it agrees children should be free to have an interest in whatever toys they like, regardless of their gender.
The books currently available are Wow! Space and Wow! Human Body, which provide "lots of amazing things" about space and the human body respectively.
During the festive season, Happy Meals will come with the choice of A Kiwi Christmas Carol and Kiwi kid favourite The Kiwi Hokey Tokey.
The addition of eight books, available in Happy Meals this year, brings the total number of books McDonald's has distributed over the last four years to over 2.4 million, making them New Zealand's largest children's book distributor.
McDonald's want to offer 20 readers a copy of all eight books. To be in to win, visit winwithheraldonsunday, put in your details and the key word "Books". Entries close at 5pm on August 9.