Last week, a report from University College London said that by 2012 the UK will be the world's fattest nation, and obesity-related illness will threaten to bankrupt the NHS. The environment we live in, with its daily barrage of junk food messaging, makes it hard for parents and children to choose healthy options.

New government rules stop junk food ads during children's TV. But they're incredibly weak – junk food ads are still running during the shows most popular with kids like X Factor and Coronation Street. Evidence says TV ads significantly affect the food choices children make. So isn't time the government closed the loopholes and stopped junk food ads before 9pm?

Children can only choose healthier foods in a society where government, schools, industry and parents work together to support them. Obese children often become obese adults, with clear implications for future levels of heart disease. We all have a responsibility to stop this happening.

We think that the government must do much more to tighten rules and protect the future heart health of our nation, specifically by creating an environment in which junk food marketing is tightly controlled and clear food labelling supported.

Whose responsibility do you think it is to reverse the current trends in obesity?

Find out how you can support our campaign here.

· Ruairi O'Connor is an Advocacy Manager for the British Heart Foundation