Jennifer Lopez, 46, Stuns Even Kim Kardashian In Racy Birthday Dress: Vegan J Lo Reunites With Casper Smart, 28 [Video]

"J.Lo and Casper never left each other's side," said the eyewitness. "They held hands when they walked in. Looked very much together."

As for Jennifer's racy birthday dress, Lopez got props from none other than the ultimate fashionista, Kim Kardashian, reported USA Today.

After assessing Jennifer's hot outfit, Kim summed up Lopez's look with a statement and a hashtag.

"Damn!!!!! How hot does @jlo look!!!!! She will forever be my idol!!!! #BodyGoals," posted Kardashian with a photo.

So how does Jennifer manage to stay sizzling at 46? Lopez swapped her normal diet for a vegan lifestyle, kicking it off with the 22-day vegan challenge done by Beyonce and Jay Z, reported Us Weekly.

"I did the vegan 22-day plan, and it was really good and I kept on with it for a few more weeks," said Jennifer. "I enjoy it. I enjoy eating that way. I never did [before]. And I didn't know how good you can feel when you put healthy stuff in your body."

Designed by exercise and nutrition expert Marco Borges, the 22-day cleanse complements 22 Days Nutrition, Marco's organic, gluten-free vegan lifestyle company.

"Psychologists have said it takes 21 days to make or break a habit. On the 22nd day, you've found the way," explained Jay Z. "You can call it a spiritual and physical cleanse."

As the Inquisitr reported, Jennifer's vegan diet helped Lopez go from a size four to a size two.

A typical day of her meat-free, dairy-free, gluten-free diet includes millet cereal with fruit for breakfast, topped with almond milk, and a kale salad for lunch. Dinner features pasta made with zucchini and tomatoes. And to satisfy her sweet tooth, J. Lo nibbles on vegan cherry chocolate energy bars.

[Disclaimer: The Inquisitr strongly recommends you consult your physician before beginning any diet or exercise program. The Inquisitr does not endorse any of the diets or diet techniques mentioned in this article.]

[Photo by Mike Coppola / Getty Images for Tony Awards Productions; Image Via Kim Kardashian / Twitter]