We all know that if you want to lose weight you need to eat fewer calories. Now, Public Health England are enforcing a new "world-leading childhood obesity plan" to tackle the number of calories that food manufacturers put in their products. Matthew Price speaks to Dr John Ashton, a public health consultant and Dr Alison Tedstone from Public Health England to find out if the new scheme is going to be enough to tackle the problem. (Image: burgers, credit: Getty Images)