Why those oh-so-healthy diet foods make us eat even more

On a diet but struggling to shed the pounds, or - horror of horrors - actually gaining weight?

Well it could be because you're on a diet, according to scientists.

A study has shown that when faced with a healthy, low-calorie dish, we instinctively increase the portion on our plate or feel justified in going back for second helpings.  Click here for full article.