The low-carbohydrate Atkins diet has become so popular that some people insist on following it when in hospital.
But one hospital's dietitians are refusing to pander to patients' demands because of fears it could hinder their recovery.
The Norfolk and Norwich University Hospital's information leaflet says that patients requiring special diets for medical or religious reasons will be provided for.
It will be reprinted shortly to make it clear that this service does not include "faddy or celebrity diets".
Eileen Duckworth, head of nutritional care, said: "The Atkins diet is not appropriate for people admitted to hospital. Losing weight is not a priority. It is not a nutritionally balanced diet, and could potentially stand in the way of patients getting better."
Serco Group has a 60-year contract to run the catering at the hospital, which opened in 2001.
Source: Caterer & Hotelkeeper magazine, 28 August - 3 September 2003