The STOP project as whole is multi-disciplinary and policy driven. As such the work proposed here will feed into downstream work packages that aim to provide policy toolkits to target the most modifiable components of causal pathways to child obesity. The use of molecular markers will strengthen the evidence regarding these causal models through the incorporation of biological and mechanistic information. Furthermore, a clinical trial will be conducted within STOP which will involve whole family intervention programmes with children who are obese. The molecular signature of obesity identified here will be measured in these children, before and after taking part in the trial, allowing highly detailed tracking of biological changes and providing further information regarding the role of these markers.