LifeLab Southampton comprises a purpose-built laboratory in Southampton General Hospital. Secondary school students visit LifeLab to learn how maternal and childhood nutrition influences health, understand the impact of their lifestyle on their future health, and experience modern science to inspire them with the excitement of research and future career possibilities. The LifeLab visit follows preparatory work in their school, which is then supplemented by later learning. Our pilot work indicated that attitudes can be changed by such LifeLab sessions. This research project aimed to assess formally the change in attitudes to health behaviours, lifestyle and interest in health and science from before to after the LifeLab experience, by conducting a cluster randomised trial with approximately 4,000 students aged 12-13 years from 18 Southampton and Hampshire schools.