But this compares to sales of £3.7 million - 270,000 copies - over the previous two years. Kiera O'Brien, at The Bookseller, said the success of clean eating authors is striking considering their low profile compared to household names.
She said: "More established cooks have huge backlists contributing to their figures - Jamie has 30 titles in the chart, Mary Berry has 47 - whereas the likes of Joe Wicks and Ella Woodward have only one or two titles out so far."
Miss Lawson has written in the past about her frustration with the "clean eating brigade".
In Simply Nigella, she wrote: "You will never hear me talking about 'healthy' food. I hate the term, but not as much as I am disgusted by the contemporary mantra of 'clean eating'.
"The clean eating brigade seems an embodiment of all my fears. Food is not dirty, the pleasures of the flesh are essential to life. We cannot control life by controlling what we eat."