There are 750 fasting blood samples that were collected from ALSPAC participants aged 7-8. Measuring metabolites levels in these samples will help us understand how metabolic changes in the body relate to various exposures and outcomes. Metabolite levels were previously quantified for individuals aged 7-8, but these metabolite levels were measured in non-fasting samples. Thus measuring these new samples will help us understand if there are any differences between metabolite levels when fasting and not fasting and how to better analyse our current data.