Mother-child cohort studies suggest an association between maternal BMI/ excessive gestational weight gain and offspring risk of cardiovascular and metabolic disease. Investigations are however complicated by inevitable confounding influences of postnatal factors which cannot always be accounted for in statistical analysis, and assumption of causality must be cautious.Randomised controlled trials (RCTs) of intervention studies in pregnant women which aim to ameliorate the metabolic influences of maternal obesity on the developing child can obviate some of these issues. The EU funded EarlyNutrition project brings together several relevant RCTs to address the influence of maternal interventions on childhood obesity and health, including the UK UPBEAT trial of a complex (dietary and physical activity) intervention in obese pregnant women. Protocols have been standardised between studies, and children will be investigated at the age of 3 and 5. Detailed measurement of body composition, breast feeding history, diet, and physical activity, as well as health, social and environmental factors will be obtained. With knowledge the maternal body composition, weight, diet and physical activity from women in intervention and control arms of the studies, these studies should provide valuable information on maternal/child obesity relationships, as well as other childhood health outcomes. Mechanistic insight will also be gained but for practical reasons this cannot be of equivalent depth to that achievable in animal models, which have provided convincing evidence for influences of maternal obesity on offspring health. Models of maternal obesity in rodents, performed under UK Home Office legislation have provided information on the mechanisms leading to offspring obesity and hypertension in the offspring, including a central role for hypothalamic centres of energy balance and autonomic pathways of blood pressure control. The offspring also demonstrate a hepatic disorder very similar to non-alcoholic fatty liver in man. These studies have led to testable hypotheses in the children of obese women, which we have now incorporated into studies of children in a mother-child cohort study (SCOPE) and from the UPBEAT trial.