Speaking at The Marketing Society's debate 'Question time: facing a fat future', McDonald's UK vice-president Julian Hilton-Johnson said the fast-food giant 'did not support' the initiative.
In December, Sainsbury's announced it would be the first of the 'big four' supermarkets to launch traffic-light labelling, using a 'wheel of health' device across 30 of its own-label products.
Many major food and drink producers have warned that they are reluctant to adopt such a generalised system, arguing that clearer on-pack nutritional information will be more beneficial to the fight against obesity.
Last month, Kellogg announced it was to introduce clearer sugar, salt and fat labelling on the front of packs. Nestle is also expected to add information to the front of its packaging.