Kemi Badenoch has robustly defended her dislike of sandwiches, telling the BBC she was "happy with my unique choices".
In an interview with The Spectator, the Conservative leader said: "I'm not a sandwich person. I don't think sandwiches are a real food, it's what you have for breakfast."
Her comments sparked a mini-political row with the prime minister's spokesman defending sandwiches as a "great British institution".
Asked about her stance while visiting a factory in Essex, Badenoch said: "I find it fascinating how interested people are in what I have for lunch."
She added: "I got asked what I like to eat and I answered the question which is something Keir Starmer doesn't do.
"But more seriously, we do need to focus on the things going wrong in country right now."
Pressed on the subject, she added: "We all have individual tastes and unique preferences.
"This world where we try and make everyone the same and then complain if a politician says something that might be different is quite wrong.
"I am someone who is happy with my unique choices, everyone should be, and we should celebrate those differences."
In her interview with The Spectator, Badenoch also said she was "not a lunch person".
Quoting the investor Gordon Gekko in the film Wall Street, she said "lunch is for wimps".
"I have food brought in and I work and eat at the same time... sometimes I will get a steak."
She also said she would not touch bread if "it is moist".
Energy Secretary Ed Miliband - who attracted ridicule when he was photographed eating a bacon sandwich in 2015 - told Sky News he wished he could "have a cross-party consensus here with Kemi Badenoch, but I can't".
"You know, I think I need to persuade her of the delights of a bacon sandwich."
Asked about her comments, a No 10 spokesman said the prime minister was "surprised to hear that the leader of the opposition has a steak brought in for lunch".
"The prime minister is quite happy with a sandwich lunch."