Let’s talk sex. Many people would rather not. It’s a difficult subject, especially if you have to be serious about it. But the consequences of not doing so are very clear: teenage pregnancies in Britain are the worst in Europe.

We live in an overtly sexual society, with images of sexual allure on display on every high street and viewable in every home at the push of a television remote or the click of a mouse. It’s hardly surprising, therefore, that many young people feel pressurised by society and their peers to have sex early.

Today, The TES begins a series of reports on the five “outcomes” of Every Child Matters, with a look at children’s health. On page 1, we report that three-quarters of teachers would like to see sex education made compulsory. The clarion call is led by primary teachers, most of whom believe it should start by nine or 10, or even sooner.

We support this view. Like it or not, today’s children are forced to grow up sooner. From an early age, they are bombarded with images of sex. Puberty starts earlier and children need to know how this will affect their bodies.

At present, sex education is only compulsory as part of key stage 3 science, which means the emphasis is on biological functions, rather than relationships or contraception. This patchwork of provision is compounded by the fact that most teachers have had no training in the subject.

The Government has taken a positive step by announcing an inquiry aimed at ensuring that young people are given good quality sex and relationships education no matter what school they attend. As Hazel Pulley, a member of the steering group, suggests, objections from a minority of parents and faith schools could be addressed by renaming the subject as “relationships education”. This should happen as soon as possible as part of a compulsory programme beginning, preferably, at age 7.

If ministers are serious about helping children to be healthy, they should also look again at how childhood obesity is measured. It’s not enough, as the first of our Big 5 series reports today, to judge growing children simply by their weight, and it can be dangerous to impose adult dieting habits on them. Children should be encouraged to eat a balanced diet, but need food that will give them energy. We should let them eat cake, even if we don’t.