Dr Michael Mosley is believed to have gone missing on a Greek island.
The 67-year-old is known for his appearances on television programmes including This Morning and The One Show.
He is also credited for the increasing popularity of the 5:2 diet for losing weight, which involves fasting for two days per week.
Representatives for Dr Mosley confirmed a search was ongoing for him, telling the Mirror that they were “very worried about him.”
A post on a local Facebook group in Greece said rescue teams from Athens were heading for the island.
READ MORE:
- Holyrood remembers 'courageous actions' of D-Day landings 80 years on
- Glasgow cinema The Vogue saved from being demolished
- Glasgow School of Art's Mack could be opened up to tourists
The appeal read: "A search and rescue team is coming from Athens with drones and other more sophisticated equipment to extend the search.
"They are expected to arrive by about 1 p.m."
The post continued: "Have you seen this man? He set off to walk back from St Nick's at about 13.30 and failed to make it home. His friends are concerned as it is 6 hours since they last saw him.
"His name is Dr Mike Mosley and he is a familiar face for many British people."
The 67-year-old broadcaster did the Channel 4 show Michael Mosley: Who Made Britain Fat? and was part of the BBC series Trust Me, I’m A Doctor.
He also lived with tapeworms in his guts for six weeks for the documentary Infested! Living With Parasites on BBC Four.
Mosley has been given an Emmy nod for BBC science documentary The Human Face, presented by John Cleese and featuring a raft of human faces including Elizabeth Hurley, Pierce Brosnan and David Attenborough.
He also advocated for intermittent fasting through the 5:2 diet and The Fast 800 diet.
Mosley has three children with his wife Clare Bailey Mosley, also a doctor, author and health columnist.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here