Major bodybuilder Kai Greene has released an e-book about plant-based dieting titled Stranded Island.
The athlete embarked on a seven-day trial of a plant-based diet after watching new documentary The Game Changers.
The 14-page book, Plant-Based Dieting - Stranded Island ($4.99), looks at plant-based protein sources and says that following a plant-based diet can leave you 'energized' and can provide all the 'vitamins, minerals, nutriets, and fiber' required for a healthy diet.
It has netted some criticism from the vegan community as the book suggests that animal protein can be part of a healthy diet, and also that bodybuilders on a cut may struggle to get adequate protein within their calorie limits on a plant-based diet.
The announcement sparked controversy online, with many people accusing Greene of 'capitalizing' on the vegan movement - after only being plant-based for around a week.
"I didn't know four days of doing something gives you enough knowledge to start educating people on it. Just proof you're doing it for money," one user commented.
While another said: "My word why are people so hateful? Kai is deeply spiritual and I'm sure veganism fits right up his alley of a strong mind-body connection. I myself just started a trial run to see if it can help with inflammation I have from a severe injury I suffered as a kid," to which Greene replied: "Respect champ!"
*This article was updated on November 4 to reflect that Greene's book suggests animal products can be consumed as part of a healthy diet.