Two Year 8 classes from Havant Academy joined up with the University of Southampton and the Lifelab facility at University Hospital Southampton to take part in the EACH-B (Engaging Adolescents in Changing Behaviour) project.
The youngsters completed questionnaires online about their eating habits, their activity levels and their wellbeing.
They will also be wearing activity tracker watches for a week, so the researchers can monitor exactly how much activity they do every day.
Next year, when these students are in Year 9, they will take part in the research again in order to measure any changes in their lifestyle habits over the past 12 months.
The students will also get the opportunity to go to the University in Southampton and visit Lifelab where they will do lots of fun practical activities focused around measuring their own health.