A 22-year-old man has left social media shocked and confused after posting a series of photographs of his age-defying mom.

Jonathan Nguyen, from Los Angeles, posted the images on Facebook, explaining his mom’s diet and exercise regime are the secrets behind her youthful looks.

“Having a young Asian mom is great until you see someone your age shooting their shot at her,” he wrote.

His followers were utterly stunned, with several explaining they thought the woman in the photograph was his sister — or even his girlfriend.

One commented: “Woah. She’s beautiful. Thought she was your girlfriend. I said to myself ‘what a beautiful couple.'”

Others begged Nguyen to reveal her secrets.

“Your mom looks like your sister, what’s her secret?” asked scores of people, while others referred to the youthful-looking mom as “goals.”

The post has since racked up over 14,000 likes and nearly 8,000 comments, with Nguyen revealing that “lots of fruit and working out every day” contributed to his mom’s good looks, as well as a low-carb, high-fat (Keto) diet.

“She works out every day, and won’t eat any processed foods for the most part. (Keto diet),” he said.

But despite sharing the images, Nguyen refused to disclose her age, explaining “it’s a secret.”

However, he later revealed to the Daily Mail that she is “in her 40s.”

“To cut to the chase my mom is in her 40s,” he said.

“She also has a skincare routine that I’m not too aware of,” Nguyen added.