He played the hunky Matt Brody in this year's highly anticipated American action comedy Baywatch, directed by Seth Gordon, based on the US TV series of the same name with David Hasselhoff and Pamela Anderson.
But a month after its release, men are still flooding Twitter with comments about Zac Efron's incredibly shredded physique in the movie, something which took great discipline and dedication to achieve with his non-existent body fat percentage.
One film-goer wrote on Twitter today: "I'd like to never see zac efron's vacuum-packed veal body ever again thanks."
Another said: "Feel like I have the body of an 8-year-old girl after watching Zac Efron in Baywatch."
A third Baywatch fan wrote: "If only I put as much effort into working out as I do to getting drunk I'd have @ZacEfron body by now."
Another stated: "Zac Efron's body is worth dying for."
Efron is in the prime of his life at 29 years old, 5 foot 8, with a waist of 34 inches. When starring alongside the blockbuster movie's main character Dwayne "The Rock" Johnson, who is internationally renowned for his chiselled body, Efron had to keep up.
According to his trainer Patrick Murphy, the actor reached 5% body fat after just 12 weeks of training. His exercise regime was constantly mixed up and was condensed into a three-day split of working back and biceps one day, legs on another, and shoulders, chest and arms on the third day. Abs would be given a little bit of attention during every session.
If you've been following Efron's career for some time, you'd know that the High School Musical star has never had excess body fat issues. His body type is an ectomorph and he most probably struggles to gain muscle mass.
For his Baywatch bod, junk foods did not get much credit in his strict diet, with Efron indulging in a cheat day every now and then. He ate extra healthy for the 12 weeks ahead of filming, with Murphy previously saying: "I implemented an all-organic whole-food diet."
His staple foods consisted of lean protein, including chicken or turkey breast (tofu, beans and legumes would be great for vegans), whole grains like brown rice and quinoa, high fibre fruits and veggies and small amounts of healthy fats such as avocados and nuts.
Efron took to Twitter to share his eating plan which included "9 days of absolutely zero carbs & sugar. Only organic grass fed/free range protein and organic leafy greens." Appetising.
Health coach Greg O'Gallagher recently made a video about Efron's secret to his Baywatch body, stating: "The truth about his physique was... he wasn't that big!
"If you ever watched the movie, what you realise is when he wears a T-shirt he's actually pretty small. He's about 160 pounds, maybe 162. The reason he looks so good when he was shirtless is because he had about 5% body fat... virtually no body fat."
Greg O'Gallagher explains Zac Efron's body composition:
"There is nothing on his waist – his waist was tiny – and that's what gave him a crazy look. He had some muscle, but nothing out of the ordinary."
"He probably has really good genetics for staying lean, having a healthy hormonal profile and a low body fat. If you look at Zac Efron over the years, he's always been lean. Most of us aren't that lucky," he continued.
So if you want Zac Efron's body, eat super clean, train super mean... and be born with Zac Efron's genetics...