German bodybuilder Fritz Horstmann completely transformed his body after switching to a plant-based diet.
The 20-year-old social media star was struggling to achieve the muscular body he wanted - until he ditched animal products altogether and gained 42 pounds in muscle.
The gym-goer, who has over 40,000 followers on Instagram, reinvented his diet after reading Dr. Greger's bestseller How Not To Die.
'No going back'
Horstmann told the Daily Mail: "I caught myself eating exactly the unhealthy animal foods [Dr. Greger] researched, finding out that they are really bad for our health.
"I decided I wanted to live longer and have a happier and more fulfilling life, and went vegetarian and shortly afterwards vegan. After seeing the environmental and animal-saving benefits, there was no going back."
The bodybuilder went from 154lbs to 196lbs, gaining what he says is pure muscle.
Horstmann revealed that he eats a variety of plant foods that range from quinoa to the occasional vegan faux meat, and lots of fruits and veggies.
He says: "I always get asked: 'Don't you lack protein because you need meat to build muscle?'
"Most of them are surprised and people that know me or see me wouldn't associate me with being vegan, maybe it's because I'm tall, pretty big and have a good presence and people think vegans are limps."
The athlete went on to say: "You know the feeling after eating greasy fries or a McDonalds Burger? I just don't want to feel that way after eating, my body basically glows from the inside with all the good, plant-based food."
"I know that I provide my body with the right nutrients, so it can thrive and I'm creating a much brighter future for me and for the environment.
"My advice for people wanting to try veganism is to find knowledgeable people on the internet, read about all the benefits, inform yourself which supplements you need to use, go slow or cold turkey, totally depends on you.
"If you want to do it slowly, then cut out eggs and dairy first, meat at the end. You can either do vegan days, three to four days a week working your way up or replacing dinner everyday with a vegan option."