Confectionery firms are to shelve some of their king size chocolate bars in a bid to tackle obesity.
Firms want to urge customers to eat in moderation
The larger Mars and Snickers bars will be among those that disappear during the campaign.
Reducing portion sizes is one of seven pledges in the first Manifesto for Food and Health.
The document, published by the Food and Drink Federation (FDF), comes ahead of a Department of Health White Paper due in the autumn.
FDF Deputy Director General Martin Patterson said it wanted to give a sign to consumers to eat in moderation.
He told Radio 4's Today programme: "There is an awful lot here for individual consumers to think about.
"But industry thinks that it can play its part too. 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".
The seven pledges include making food labels clearer, improving certain products by continuing to reduce sugar, salt and fat levels as well as providing lower salt, sugar and fat options where possible.
FDF members, which include companies like Coca-Cola, Kellogg's, Kraft Foods, Nestle, Pepsi and Weetabix, will help to reduce over-consumption by phasing out king-size bars in 2005.
Primary schools will remove all vending machines unless specifically requested, according to FDF members.
Secondary and primary schools will also remove branding from vending machines on request and choices will be broadened.
Companies will participate in a government-led campaign of public education on healthy eating and healthy lifestyle by delivering messages on product packaging.
FDF members will work with the government and Ofcom to tighten self-regulatory codes in terms of advertising.
They aim to promote healthy workplace programmes on diet and lifestyle within firms involved in the food industry.