Patients with impaired kidney function would be wise to go easy on their watermelon consumption, with US doctors warning it has the potential to induce severe hyperkalaemia.

Watermelon is often “overlooked” as a high-potassium food despite two wedges (or an eighth of a melon) containing approximately 640mg of the mineral, said the team from Saint Vincent Hospital in Worcester, Massachusetts.

Their case series involving three adults revealed a sweet tooth for watermelon led to life-threatening spikes in serum potassium levels.

The first case involved a 56-year-old man with insulin-dependent type 2 diabetes and stage IV chronic kidney disease (CKD) who presented with a 15-second episode of syncope.