This work aims to understand the mechanisms by which organisms use nutrition to enhance fitness. The project uses novel genomics techniques to: 1) develop diets to improve fitness with stress and ageing, and; 2) to understand the molecular underpinnings of these improvements. Food availability is a key predictor of evolutionary fitness. Surprisingly, recent data shows that some key assumptions informing how these predictions are realised are not strictly correct, thus exposing a lack of important mechanistic knowledge. This project seeks to understand these mechanisms. The project aims to expand academic knowledge of fundamental nutritional biochemistry, and ultimately improve predictions of species' responses to environmental change.