Prometeus will implement the first neonatal metabolic model describing the effects of nutrition on brain oxygenation, blood flow and metabolism. The model will be initially implemented based on data from an animal study in Sprague Dawley rats, due to their brain anatomical and functional proximity to the preterm newborn. Rats will be fed with different diets (high/low fat and protein) and put into hypo (low blood sugar) or hyperglycemia (high blood sugar).