Labelling standards vary across the globe, but proposals for discussion at the meeting next month in Rome will seek approval for percentage labelling .
Created in 1963 by UN bodies, the Food and Agriculture Organisation and the World Health Organisation, Codex Alimentarius develops food standards and guidelines for codes of practice in the global food chain.
Key principles embodied in Codex are consumer protection, fair practice in the sale of food, and facilitating trade.
Europe is backing the Codex label proposals: not surprisingly because the EU25 bloc already has similar rules in place.
Article 7 of European Directive 2000/13/EC determines the circumstances in which the quantity of the ingredients of foodstuffs must be declared on the label.
The legislation is based on the fact that a link may be established between the quantity of one or more ingredients in a product and the choice a consumer makes.
Generally speaking, the quantity of an ingredient must be mentioned: where the ingredient is included in the sales name of the product or is normally associated with that name; where the ingredient is emphasised on the label; where the ingredient is essential for characterising the product.
In a position statement on the Codex proposals Europe said that it "however questions the justification and the objective need to show systematically the quantity of each ingredient above a certain percentage by weight in relation to the total weight of the product (for example 5 per cent)."
Global consumer groups are also backing the proposals because they believe the percentage label will lead to greater transparency for the consumer, and fuller knowledge to make a choice.
The US, however, that does not have the quantity ingredient rules is against the Codex proposals. Regulators - the FDA - oppose percentage ingredient labelling; one key contention is over the threshold amount of ingredient that would trigger listing.
If the delegates at Codex do eventually approves a percentage labelling standard, US companies are not obliged to follow it. But those with global trade would have to comply in countries that adopt the standard.
Many countries, notably developing countries with growing markets, adopt Codex standards because they lack the resources to set food safety and nutrition rules themselves.