Patricia Daly knew Domini Kemp before they met. In that two degrees of separation way they had a couple of mutual friends. But it wasn’t until 2013 when Kemp came for a consultation that Daly realised the friends who insisted the two would get along like a house on fire were spot on.

Both women are working mothers with two children apiece. Both have had cancer, twice. And both were convinced that food was something they could use to help them get through treatment and onwards. Now they’ve published The Ketogenic Kitchen, a collaboration cookbook based on what they learned and ate through illness to wellness.

The book comes in the middle of a clean-eating wave that can feel like the attack of a clone army. Beautiful 20-something women report glowing skin and endless energy from wheat-, dairy- and sugar-free diets making dates and coconut oil sound like a recipe for immortality served with a side order of fabulousness.

The buzz about nut butters is a mixed blessing. Do they hope keto (short for ketogenic) is going to become the new paleo? Kemp and Daly both do a grin-grimace at the question. “I actually hope it doesn’t,” Kemp says. Britney Spears and comedian Melissa McCarthy have been reported to be eating by the keto rules: manna from publishing heaven. But Kemp is not delighted by it, not least because of the backlash that inevitably follows the adulation of another trendy diet. “You don’t want it to become a fad. It’s metabolic therapy. It is such a serious thing and has such serious benefits for some people.”