Whilst other studies exist elsewhere charting the metabolome of disease or of adult or mid-to-late age participants, there are few examples of longitudinal metabolomic data. ALSPAC does have proton nuclear magnetic resonance spectroscopy data on an extended lipidome and select protein panel (Nightingale), however data do not exist for longitudinal liquid chromatography/mass-spectroscopy derived metabolites. This approach has the potential to substantially expand the metabolite collection in ALSPAC, to allow new association analyses and also to provide a benchmark or longitudinal standard for circulating metabolites across ages. This work proposes to collect new data (from existing samples) under a sampling framework aiming to maximise capture of longitudinal changes in metabolic profile.