Beyoncé Knowles revealed to Oprah Winfrey Saturdayin an interview that she gained 57 lbs. during her pregnancy with daughter Blue Ivy. The mom’s personal trainer, Marco Borges, reveals that she lost the weight with the help of a partially vegan diet.

Borges spoke with Life & Style magazine and detailed that in addition to fat-blasting cardio, he recommended Beyoncé have at least “one vegan meal a day, because this typically gets people to eat more greens than they normally would."

"Consistency is the key to success," he told Life & Style. "I love running-spring intervals for quick cardio sessions and also ... running stairs."

Beyoncé divulged to Winfrey that she was performing just three months after giving birth and had to quickly work on getting in shape.

"Y'all have no idea how hard I worked," she was quoted as saying at that time. "They had me on that treadmill. I ate lettuce!"

The R&B diva reportedly also incorporated vegan meals into her diet while still pregnant, something husband Jay-Z also joined in on, according to Us Weekly.

A source told the magazine that Jay-Z was “trying to be disciplined” in their partially vegan diet in order to have energy to support his then-pregnant wife.

Beyoncé also told 20/20 in a 2011 interview that she was working hard to stay healthy during her pregnancy.

"I've been really conscious [about food]," she said. "I've been trying my best not to lose control!"

Now that the superstar singer is back in fighting form, she reveals that she has protein shakes as a meal replacement when she’s on the run and enjoys making her workouts fun with music.

"I'll put on a song that I really like and do biceps curls with 5-pound weights for the whole song," Beyoncé said, according to Us Weekly.

Beyoncé notably lost 20 lbs. doing the Master Cleanse diet for her role in the movie “Dreamgirls,” something she has reportedly sworn off of doing again.

Now, she apparently abides by Borges’ suggestions of snacking on edamame instead of potato chips, as well as green apples or cucumber sprinkled with vinegar, cayenne pepper and lemon.

"If you have to snack, don't sacrifice nutrition," the trainer told Life & Style.