Reducing the exposure of children and young people to the marketing of unhealthy foods is a core strategy for reducing the high overweight and obesity prevalence in this population. The Advertising Standards Authority (ASA) has recently reviewed its self-regulatory codes and proposed a revised single code on advertising to children. This article evaluates the proposed code against eight criteria for an effective code, which were included in a submission to the ASA review process from over 70 New Zealand health professors. The evaluation found that the proposed code largely represents no change or uncertain change from the existing codes, and cannot be expected to provide substantial protection for children and young people from the marketing of unhealthy foods. Government regulations will be needed to achieve this important outcome.