Venus Williams looked tired today. Earlier in London, Elena Vesnina of Russia dominated the five-time Wimbledon champion, winning in straight sets 6-1, 6-3.

Williams had lost in the second round at the French Open, her first Grand Slam action since Aug. 29, 2011, at the U.S. Open; two days later, she pulled out of her second-round match at that tournament, revealing that she’d been diagnosed Sjögren’s (show-grens) syndrome, a little-known autoimmune disorder.

Since that health disclosure, Williams, 32, quietly announced she would try a raw vegan diet, hoping that this change in her diet would help mitigate the pain and lethargy commonly experience by Sjögren’s sufferers. But judging from today’s listless performance, Williams is struggling to balance her diet and tennis schedule.

Although Venus showed the class and grace of a champion during her post-match press conference, making sure to congratulate Vesnina and keep all talks of retirement mute, there is no doubt that, behind all her positivity, Williams wanted to have a better showing on the Wimbledon grass, by far her favorite and most successful surface.

But I hope no one thinks her allegedly vegan diet is the blame for her poor play. Just recently, boxer Timothy Bradley conceivably dispelled all myths about the lack of protein, energy, and performance while on a world-class athletic stage after he out-classed the wildly popular Manny Pacquiao early this month.

Conversely, a vegan diet can be mismanaged, causing all kinds of trouble for athletes. Countless former-vegans challenge the benefits of a strict vegan diet, but most of the time, those issues usually stem from not adhering to proper nutritional balance, which could be said for athletes on any diet.

Whatever the case, Williams says that her main goal is to compete successfully in the upcoming London Olympics, and there is no reason not to believe her. Williams was making her 16th straight appearance at Wimbledon and had not lost in the first round since her debut.