We present the elaboration of an informatic program (Informatic Logic Support [SLI]) as a clinical help in diagnosis and treatment, for use by compatible computers PC. In this first part dedicated to artificial nutrition, we explain the scientific support, the capture of anthropometric and biochemical data, the processing, the results and the conclusions delivered by the computer that inform us about all the calculated nutritional parameters the type of malnutrition, the surgical risk of morbimortality (nutritional prognostic), and the caloric needs.