My PhD is focused on how hydration and breakfast influence blood sugar control and appetite. The first trial involves testing the acute glycaemic and appetite response after being dehydrated versus rehydrated. Studies 2 and 3 involve analysing data in order to find trends in what people eat at breakfast, how it corresponds to what they eat later in the day and certain health outcomes. The final intervention aims to investigate whether sweet food at breakfast changes what people eat later in the day, as well as whether this is metabolically a better time of day to be eating sweet.