Dr Xand van Tulleken and his brother, Chris, have recommended a superfood which is so healthy they say it 'tastes like medicine'. The duo were talking on the BBC Radio 4 podcast What's Up Docs?

The duo are well-known for recommending healthy changes to both diet and exercise - and this was no exception. Chris brought in a fruit known as kumquats for his brother to try.

Known for their sharp, sour yet sweet flavour, he struggled at first but gradually warmed to them. Small, oval, and similar in appearance to a tangerine, kumquat combines the Chinese words 'gam', meaning gold, and 'gwat', another word for tangerines.

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You eat the entire fruit, skin and all, and they are incredibly healthy. They have about 13 calories each and no cholesterol, and are packed with fibre and antioxidants.

"That's a real wake-up-in-the-morning fruit," said Chris as he tried one. "It's good, isn't it?" Xand responded.

"I'm not a big believer in kind of superfoods that any one particular food is worse or better than any other particular food," said Chris. "It's such a challenge."

"Yeah, but these taste like they're really good for you, because the peel is so bitter, it tastes like medicine," said Xand. "I think you're treating this as some kind of incredible adventure, whereas people just eat these for pleasure, Chris. It's not meant to be some ordeal of truth, you know, it's just like you just have it."

"It's a very pure, bitter, sour, sweet, all at once," Chris said. "I work on food and I was surprised to find a whole common food in the supermarket which I have simply never eaten.

"I do go and do this for the girls, and they loved another fruit that I hadn't had until recently, which was a Sharon fruit. Persimmon? I don't know why anyone would like that."

Xand added: "I feel like it's good, particularly if you've got kids. Like, go and buy something you haven't had before."

According to WebMD, kumquats are high in vitamins C and A. Vitamin X is important as your body does not make it naturally. It helps blood vessels, cartilage, muscle, collagen, and healing.

Vitamin A is an important antioxidants and helps things like vision, growth, reproduction, and immunity. It protects your cells from the effects of cancer-causing free radicals.

Around 92 per cent of Brits do not eat their recommended 30g of fibre every day, but kumquats are also high in this. It can help you lower your cholesterol and blood sugar.