From cheesecake-stuffed strawberries to diet cola chicken, a collection of slimming recipes which started life as a food blog has toppled political tomes and celebrity memoirs to become the fastest selling non-fiction book since records began, racking up more than 200,000 sales in three days.

Pinch of Nom by Kate Allinson and Kay Featherstone went on sale on 21 March and 72 hours later it had sold 210,506 copies, according to book sales monitor Nielsen BookScan – the highest single week sale for a non-fiction book since Nielsen began to track sales in 2001.

This puts Allinson and Featherstone ahead of Jamie Oliver, whose book Jamie’s Italy sold 154,769 copies in one week in 2005, and previous record holder Peter Kay, whose memoir The Sound of Laughter sold 165,462 copies in a week in 2006.

Pinch of Nom’s first week sales are only beaten by eight other titles – five of which are by JK Rowling, two are by Dan Brown, and one of which is by EL James. “Perhaps most shockingly of all, it knocked Mary Berry’s Quick Cooking from the hardback non-fiction No 1 — I repeat, Mary Berry has been knocked from the hardback non-fiction No 1 spot before Mother’s Day,” marveled the Bookseller’s charts and data editor Kiera O’Brien.

Allinson and Featherstone owned a restaurant in The Wirral where Allinson was head chef, before launching their blog in 2016 which set out to “provide some helpful info for fellow dieters, to show just how easy ‘diet’ food is to make”. Offering recipes from Slimming World-friendly fishfingers to a “syn-free” Mexican chilli beef, each of Pinch of Nom’s recipes is tested by around 20 of the site’s 1.5 million community members.

Having signed the book deal with Pan Macmillan imprint Bluebird last year, Allinson and Featherstone entered the book charts last week ahead of bestselling authors including David Walliams, whose latest children’s book Fing sold 187,000 copies less than Pinch of Nom.

“We have been absolutely blown away by the support for this book from our community, booksellers and everyone who has picked up a copy this week,” said Allinson and Featherstone in a statement. “We know it can be hard to be inspired in the kitchen if you are trying to lose weight and all we ever wanted to do with Pinch of Nom is to help people create delicious home cooked slimming meals that don’t taste bland or boring. To think that the book is out there being used in kitchens across the UK is incredible and we really want to thank our Pinch of Nom community.”