Yoko Ono and John Lennon
Yoko Ono gave her ex-Beatle husband John Lennon his favourite treat of chocolate, despite their strict diet, the weekend before he died, in whay became a poignant moment.. REUTERS/Toshiyuki Aizawa

Diet-obsessed Yoko Ono surprised her ex-Beatle husband John Lennon with a bag of chocolates - his favourite treat but one she had been denying him - in what turned out to be a poignant moment in their last weekend together before he was murdered.

Avant-garde musician and artist Yoko was sharing her food memories on BBC Radio 4's Food for Thought series.

"John loved chocolate and at one point I said let's not have any chocolates, don't even have [them] in the kitchen," 78-year-old Yoko told presenter Nina Myskow.

"And then the last weekend [before his death] I just went out to get newspapers and a little breather, and I don't know why I thought about it, but I thought I'll get him a bag of chocolates, just to surprise him.

"So I did. He was so surprised. He said 'are we going to do this? Great.'"

Yoko added: "The last weekend I gave him something that he loves."

She told Myskow that she used to dislike chocolate but now eats it as it reminds her of the former Beatle.

He was shot four times in the back on 8 December, 1980, by crazed Beatles fan Mark David Chapman.

Chapman, who is still in prison, was said to be angered by his hero's remark that the Beatles were "bigger than Jesus".

Yoko also reminisced about the time that John suggested they go on a 40-day juice diet "because Jesus Christ went up in the mountains for 40 days [so] there must be something about it ... that you get this incredible awareness, or something".

She had just given birth to their son, Sean.

But after 40 days he told her that he was not getting any special awareness.

The first traditional British meal that he introduced her to after they met was fish and chips, she told the programme.

"Chips are not junk food. Fish and chips? They are beautiful," she said.

"I did not know about fish and chips until John [Lennon] said 'have you ever had fish and chips?' I said 'no'. He said 'okay' and got me my first fish and chips.

"He said 'make sure to get the one with newspaper around it'. It was just at the time they were going to prohibit wrapping a newspaper around [chips] as it was unsanitary, or something."

As healthy eating goes, Ono recommended the Korean dish kimchi, a spicy, fermented condiment.

"Many people say that Koreans are probably very healthy - they are. Because of kimchi," she said.

"Just be very careful that it doesn't say there's monosodium glutamate in it."