Marmite: we’re constantly told we either love or hate the sticky, yeasty stuff. But rarely do we hear of its life-preserving qualities.

For fusspot John Pearson, however, it’s his aqua vitae. The Derbyshire food-hater only eats 10 things -mostly carbs - including Marmite. He reckons he gets through a kilo of it a month, and credits the vitamin B-tastic spread with keeping him healthy - enough to get a black belt in karate.

Unless… he’s just got some Marmite on his belt. We’ll never know.