James Martin unveils the surprising two ingredients behind his three-stone weight loss

Martin confessed that his passion for motorsport spurred his decision to slim down (Image: Getty)

Celebrity chef James Martin, 52, best known for his ITV show James Martin's Saturday Morning, has divulged his astonishing two-ingredient diet, which led to him losing a massive three stone.

On the Spooning with Mark Wogan podcast, Martin confessed that his passion for motorsport spurred his decision to slim down, explaining: "It comes down to the fact that I race cars, or I still try and race a few cars, and I actually struggle to get out of them now.

"Getting in them, you kind of fall in them, but then you've got to get out of them, and it just doesn't look very good."

The star disclosed that he'd been predominantly consuming fish, which now constitutes a whopping 80 percent of his diet, and butter as part of his successful weight management strategy, Gloucestershire Live reports.

He added: "I've decided that I maybe need to stay clear away from these (picks up a Twix bar) and stuff like that and maybe eat fish, and it's worked."

The star disclosed that he'd been predominantly consuming fish (Image: Getty)

In an intriguing twist, Martin has also authored a 517-page ode to butter titled 'Butter: Comforting, Delicious, Versatile - Over 130 Recipes Celebrating Butter', showcasing his love for the dairy delight.

"When everyone brought a book out about healthy food about five years ago, I brought out a book on butter", he said.

Martin has opened up about his deep-rooted passion for butter, attributing it to his upbringing: "I'm a farmer's kid, I like pure food, I like simple food and just love great ingredients.

Martin has also authored a 517-page recipe book showcasing butter (Image: Getty)

"I like simple cooking, but also bringing out the flavour of the ingredients is more important than anything else."

Martin, who owns several restaurants and bakeries, has managed to shed pounds without resorting to exercise, quipping: "I don't go to the gym. (His weight loss) comes down to the fact that I can get my a**e in and out of a car."

Cooking talent runs in his family, although James is the only one to turn it into a professional career.

He honed his skills in France before returning to the UK to work in various restaurants, eventually becoming a familiar face on television from the mid-90s with appearances on BBC and ITV cooking programmes.