Consuming low-calorie food may have a protective effect against some diseases as the number of calories a person eats directly influences the performance of various cells, researchers say. The study on mice showed that a low-calorie diet can protect the brain from neuronal cell death associated with diseases such as Alzheimer's, Parkinson's, epilepsy and cerebral vascular accident Researchers at the University of Sao Paulo in Brazil. were looking at how changes to the diet affect metabolism and how that ends up changing the odds of having diseases associated with ageing.