Matthew Gillman (Harvard School of Public Health) discussed early intervention to interrupt the vicious, intergenerational cycle of obesity. The LIMIT and Healthy Moms trials both investigated the impact of limiting weight gain in overweight and/or obese pregnant women by delivering dietary and lifestyle advice (LIMIT), or group-based, weight management intervention (Healthy Moms). In LIMIT, there was no difference in gestational weight gain between lifestyle advice and standard care. In Healthy Moms, which was undertaken in obese women only, the intervention group gained an average of 3.8 kg less weight compared with the control group and also had a reduction in large for gestational age infants (9% vs 26%). These data are encouraging, and although not yet proven, interventions that prevent excessive gestational weight gain in overweight and obese women may be a promising strategy to reduce the risk of childhood obesity.