Even as others grow pot bellies as they age, TV actor Zheng Geping, 50, has carved out rock-hard abs.
And as Mr Zheng shared in his book Star Fitness, he achieved these the hard way and did not take any fat-burning pills.
So imagine his shock when he saw photographs of himself with his chiselled torso in an online advertisement for supplements that promise lean muscles in "only a few months".
The ad, which came out over the weekend, also showed photos of Filipino professional boxer Manny Pacquiao, Hong Kong actor Nick Cheung and Taiwanese Canadian actor Eddie Peng.
It claimed that these celebrities had achieved their ripped, beach-ready bodies after consuming Nitric Max Muscle and Anabolic Rx24.
But at least one person has had problems after taking these two products.
In response to queries from The Straits Times, the Health Sciences Authority (HSA) said it has received one "adverse-event report" of a patient who developed rashes and a change of bowel habits.
"The patient had purchased the products online through the overseas website BioTrim Labs. Laboratory testing of the products is ongoing," said its spokesman.
The two products are known to be sold only online.
Mr Zheng said he found out about the ad from a friend, who told him it was put up by a United States company.
He said: "What worries me is that the company claims to provide free shipping to all destinations around the world. I have not taken any of those supplements and I do not know if they are safe to consume.
"My photographs were used without my permission and I do not endorse those products. I feel the need to warn the public against taking them."
HSA strongly advises consumers not to buy health products online. Nor should they buy them from street peddlers or even well-meaning friends or relatives.
"Health products sold on the Internet pose a high risk of harm to consumers as there are no means to verify the source, safety and quality of these products," an HSA spokesman said.
"They are often produced under poor manufacturing conditions with no proper quality controls and by unscrupulous persons who have little regard for the health of the user."
Mr Zheng also wanted to emphasise that there is no secret or miracle pill that could help one achieve a body like his. "It won't happen overnight. It took me about six months to achieve a body like Bruce Lee's," he said.
"I put in a lot of hard work, going to the gym at least three times a week and running on alternate days. I also had to follow a strict diet."
He said he does not plan to take any action for now, although lawyer Chia Boon Teck believes he could sue for defamation.
Said Mr Chia: "A similar case was heard in the High Court in 1995 when Mr Chiam See Tong successfully sued a restaurant for using his photo to attract customers to the restaurant and was awarded $50,000 damages.
"If the advertiser is US-based, I would advise Mr Zheng to consult American lawyers on the possibility of suing in the US.
"Given that product endorsement by celebrities is a billion-dollar industry in the US, I don't think they would take kindly to an advertiser using a celebrity's image without his endorsement."