A number of big name brands have been accused of reducing the size of their products while keeping the cost the same.
In a term dubbed "shrinkflation", consumer magazine Which? says one of the worst examples is Cadbury's, who reduced the number of Creme Eggs in a box from six to five in the run-up to Easter.
Confectionery companies argue a reduction in the size of chocolate bars is not all about rising production costs but is also an attempt to fight obesity.