21/03/2014 08:33 GMT | Updated 21/05/2014 06:59 BST

Don't Give Junk Food Marketers a Place on the Sofa

You might not even realise it, but junk food marketers sneak unhealthy products into our homes every day. How? They find a way in through our TV screens, laptops, and smartphones.

Our children are exposed to invasive marketing in their own homes and parents are powerless to stop it.

When we sit down to watch our favourite family TV programmes, our children could be seeing as many as eleven junk food adverts an hour. These are adverts that are banned from children's programming, but loopholes in regulation mean that young people are bombarded with ads when their TV viewing actually peaks - around eight pm.

Research from Action on Junk Food Marketing revealed this week that junk food ads strive to appeal to a younger audience. A study found that nearly a third of food adverts between eight and nine pm used themes of 'fun' rather than adult concerns such as price or convenience. Over half of them used children or child-aged characters to push their products.

As a mum, I know how appealing these adverts are to kids. I'm sure I'm not the only parent who has looked down during the supermarket shop to see a pleading face proffering the latest snack, cereal or drink that they've seen on TV.

What's more, TV is only one part of the story. An ad break only lasts three minutes, but product promotion lasts much longer. In the Action on Junk Food Marketing research, around a third of ads studied ended with a website or Twitter hashtag. We know that young people are never far away from their phone or computer - junk food marketers know this too.

Thirty six per cent of 8-15 year olds use smartphones or laptops 'most times' when watching TV. Playing a game, entering a competition or following a brand on Facebook may not feel like advertising, but companies invest millions of pounds in these subtle techniques to get teenagers hooked.

With around a third of UK children now overweight or obese, we should be doing more to protect young people from sophisticated marketing techniques.

If you're not sure that this is a problem, you need to look no further than the playground gates. Our research has told us three quarters of parents (75%) want the Government to strictly regulate junk food advertisements and 65 per cent are in favour of a 9pm watershed ban to shield kids from ads on TV.

As part of my work with the British Heart Foundation, I've been banging the junk food marketing drum for some time. But I'm not alone - doctors, health specialists and parents are all joining my call. Now Action on Junk Food Marketing has been formed to give us all a voice which we can use to fight back against the marketers.

We are calling on the Government to switch off junk food TV adverts before nine pm and put rules in place to stop children becoming fair game for internet marketing. Sign our petition and help us to ditch the junk.