Medicine is and always has been full of unproven concepts. However, wh
en they are frequently used in clinical practice, they seem establishe
d and are therefore seldom questioned. In his book 'Follies and fallac
ies in medicine' (Glasgow, The Tarragon Press, 1989)Peter Skrabanek cl
early proposed a way to improve the quality of medicine by being chron
ically sceptical towards all 'established' concepts. By cyting Bertold
Brecht he proposed 'scepticemia' as a major tool to speed up the prog
ress in medicine: 'The chief cause of poverty in science is imaginary
wealth. The chief aim of science is not to open a door to infinite wis
dom but to set a limit to infinite error.' In this article we will try
to analyze the evidence of the three so-called cornerstones of diabet
es therapy diet, exercise and insulin - with regard to their efficacy
in reaching the goals of treatment in type 1 (insulin-dependent) diabe
tes.