Beyonce and JAY-Z are urging fans and followers to adopt a plant-based diet in the introduction for a new book.

Beyonce's trainer Marco Borges has released The Greenprint: Plant-Based Diet, Best Body, Better World and in the book, the Drunk in Love hitmakers open up about the changes they've made at home to eat better and live healthier now they are parents to young kids.

"Having children has changed our lives more than anything else," they write. "We used to think of health as a diet - some worked for us, some didn't. Once we looked at health as the truth, instead of a diet, it became a mission for us to share that truth and lifestyle with as many people as possible."

Beyonce and JAY-Z first adopted a vegan diet in 2013, when they embarked on a month-long challenge, and in 2015, Beyonce teamed up with Borges to release a vegan food plan.

"They loved it," Borges previously told People magazine. "They walked away with a greater understanding of the powerful benefits of plant-based nutrition. They were getting people saying, 'Your skin has this glow'. And who doesn't like being told they look awesome?"

Over the years, the couple has increasingly begun to adopt more plant-based meals into their diets for longer periods of time and JAY-Z and his wife now believe it is their responsibility to inform others about the benefits of going vegan.

"We all have a responsibility to stand up for our health and the health of the planet," the superstar couple writes in the book. "Let's take this stand together. Let's spread the truth. Let's make this mission a movement. Let's become 'the Greenprint'."