Buchinger Wilhelmi Marbella

The Mediterranean sister to the Lake Constance original, opened in 1973 by Otto Buchinger's daughter Maria and her husband Helmut Wilhelmi, and set between the Sierra Blanca mountains and the sea about three kilometres from Marbella old town.

Maria became the family's second major figure — known internationally as the 'Grande Dame' of therapeutic fasting, awarded the Federal Cross of Merit in 1995 and named Marbella's Entrepreneur of the Year in 2003, the first woman and first foreigner to receive it. Her grandson Victor Wilhelmi manages the clinic now.

The method is identical to Überlingen: physician-supervised fasting, staged refeeding, and the same research programme behind both. What differs is climate and register. The main building is a Spanish hacienda with terracotta arches and palms, and one visiting journalist described the effect as combining the serenity of a monastery, the luxury of a five-star hotel and the efficiency of a medical facility.

The clinical reality is never far away, though. Bedside emergency bells connect to a nurse, the therapeutic waters come colour-coded, and there is no minibar.

Choose Marbella over Bodensee for the sun and the softer setting; the medicine is the same either way, and anyone choosing on climate should know the fast is no easier for it.