Nazanin Zaghari-Ratcliffe, the British-Iranian woman jailed in Tehran for alleged spying, has ended her hunger strike after 15 days.
Her husband Richard, who was on hunger strike with her, told the BBC he was "relieved" and he "wouldn't have wanted her to push it much longer".
She told him on the phone on Saturday morning she felt nauseous, he said.
Mr Ratcliffe, who has been camping outside the Iranian Embassy in London, said he had also now eaten.
Mrs Zaghari-Ratcliffe, from London, was jailed for five years in 2016 after being convicted of spying, which she denies.
"I had a phone call this morning and it's good news - she's decided to stop her hunger strike, which means that I'll be stopping it," her husband told Radio 4's Today programme.
"I'm very relieved I have to say. It was getting hard for me, but I'm sure it was much harder for her."
His wife was under "quite a lot of pressure" from the Iran's Revolutionary Guard to break her strike, Mr Ratcliffe said.
She ate some porridge with apple and banana for breakfast on Saturday, he added.
Asked what the joint hunger strike had achieved, Mr Ratcliffe said more than 100 MPs had visited him outside the Iranian embassy to "show solidarity" with his wife, and her case had received media attention around the world.
"In Iran, we've become a much bigger story than we were before and there's an awareness that really this needs to be solved," he said.
The protest made Iranian diplomats in London "cross", with some "trolling" him on social media, he said.
Among those who visited Mr Ratcliffe outside the embassy during his protest were Defence Secretary Penny Mordaunt and Labour leader Jeremy Corbyn.
According to Mr Ratcliffe, Mr Corbyn said he would try to liaise with the Iranian ambassador - an offer he said he welcomed.
After ending his hunger strike, Mr Ratcliffe said he planned to seek medical attention and then meet with his local MP, Tulip Siddiq, to discuss whether Parliament could do anything to help in his wife's case.
Ms Siddiq said it was a "huge relief" the couple had ended their hunger strike.
"It shames those in power that they had to go through that torture in the first place. We will bring her home," she said in a Twitter post.
A huge relief that Richard Ratcliffe and Nazanin have stopped their hunger strike. It shames those in power that they had to go through that torture in the first place. We will bring her home #FreeNazanin— Tulip Siddiq (@TulipSiddiq) June 29, 2019
Director of Amnesty International UK, Kate Allen, said although their hunger strike was over, "the deep injustice of this case isn't".
Urging the Iranian authorities to release Mrs Zaghari-Ratcliffe, she said: "Nazanin is still a prisoner of conscience, still unfairly jailed after a sham trial, and still being subjected to the torment of separation from her home and family."
Comedian Shappi Khorsandi, who has campaigned for the mother-of-one to be freed, also tweeted: "They are both so strong and climbed a mountain to draw attention to unspeakable cruelty by state. They were heard."
Foreign Secretary Jeremy Hunt has previously urged Iran to "do the right thing" and release Mrs Zaghari-Ratcliffe.
"Our message to Iran is whatever the disagreements you may have with the United Kingdom, there is an innocent woman at the heart of this," he said.
Mr Hunt granted Mrs Zaghari-Ratcliffe diplomatic protection in March, but Tehran refuses to acknowledge her dual nationality.
Mrs Zaghari-Ratcliffe was arrested at Tehran's Imam Khomeini Airport in April 2016 and has always maintained the visit was to introduce her daughter, Gabriella, to her relatives.
She is serving her five-year sentence in Tehran's Evin Prison.