If there's anyone who knows a thing or two about keeping your body in tip-top shape, it's sisters Venus and Serena Williams.
And while the former may be older, she recently admitted that it was her little sister who gave her the wise suggestion of going vegan.
"Plant-based definitely changed my life, it made my skin amazing," Venus told Insider.
The athlete was so happy with the effects that she even launched her own line of vegan protein, Happy Viking, last year.
"I need to refuel and provide protein to my muscles quickly after I work out for recovery and to maintain muscle," she noted. "So Happy Viking was created to fuel your inner fighter, your inner Viking, while feeling happy and satisfied about what you put in your body."
The nutrition line is also free of gluten, soy, GMOs and artificial ingredients.
Venus first took on the diet because of her autoimmune disease, Sjögren's Syndrome, which causes symptoms like joint paint and fatigue — two things that threatened to derail her career.
However, after making the lifestyle swap, she noticed a huge improvement.
"Things can get a little tricky and you can be on loads of medicine, and that's not something that I want to do," Venus explained. "So to be able to control as much as I can — what's happening in my body, my inflammation levels — through what I eat is a godsend."
Since taking her sister's advice, she's loosened up the restrictions around her diet.
In the beginning, Venus stuck to being a "raw vegan," which means she ate only raw, plant-based foods. But now, the self-professed "junk food junkie" allows herself to indulge when the craving strikes.
"I've never met a French fry that wasn't vegan. I'm definitely not a robot," she pointed out. "You can reward yourself and have fun eating as well. There are so many more athletes doing it and sometimes they ask me how to do it. So, I tell them, 'Hey, sometimes you just have to have some pie.'"