Confectionary manufacturers today announced the phasing out of some king size chocolate bars in a move intended to tackle rising levels of obesity.

King size Mars and Snickers bars could disappear next year under seven pledges set out by the industry association, the Food and Drink Federation, to make products healthier.

The pledges come ahead of a health white paper due to be published later this autumn. They include clearer labelling, reduced fat, sugar and salt levels, the removal of vending machines from schools, and a rethink on some portion sizes.

The federation's deputy director general, Martin Patterson, said it wanted to encourage consumers to eat in moderation. "There is an awful lot here for individual consumers to think about, but the industry thinks that it can play its part too," he told the BBC Radio 4 Today programme.

"If, for example, we mark up a product for sharing, and that is backed by a general understanding that perhaps two products in one day is more than moderate, then we are starting to get somewhere".

However, the food and farming campaign organisation Sustain said it did not consider the pledges to be very impressive.

"It's half-hearted, and the industry won't be able to claim it is behaving in a responsible way until it stops it aggressive advertising of unhealthy foods to children," a spokesman said.

In May, a House of Commons health select committee report warned of a growing obesity epidemic. It recommended that the government consider direct regulation of the food industry if the industry had not proved itself to be tackling the problem in three years.

According to British Heart Foundation figures, Britain has the fastest-growing rate of obesity in the developed world. In 10 years, the percentage of obese adults has risen by more than 50%, from 14% of the population to 22%.

Around a quarter of children - 22% of boys and 28% of girls - are overweight or obese, and 85% of men and 69% of women eat too much salt.

The food and drink industry is the largest manufacturing sector in the UK, with an output of more than £66bn and 500,000 employees. Members of the Food and Drink Federation include Coca-Cola, Kellogg's, Kraft Foods, Nestle, Pepsi and Weetabix.