The European Parliament has passed new laws to clamp down on misleading claims on food product labels.
Claims must be backed by science
All foods that make a new health claim will now have to be checked before they go on sale.
Statements such as 'low fat' will have to meet a standardised definition agreed by the EU.
And foods that make a nutrition claim - such as being low in salt - will have to make it clear on the same label if they are also high in fat or sugar.
In addition, foods that are high in more than one nutrient will not be allowed to make a nutrition claim about another of its ingredients.
The parliament also approved new rules on adding vitamins and other minerals to foods.
The new laws are expected to be phased in over the next three years.
EU Health and Consumer Protection Commissioner Markos Kyprianou said: "The new laws will ensure that consumers will be able to rely on the truth and accuracy of information on food labels.
"It will create a level playing field for food manufacturers wishing to use health or nutrition claims."
Jill Evans, a member of the parliament representing Plaid Cymru, welcomed the new measures.
She said: "The food industry will no longer be able to try and dupe its customers with false promises."
Michelle Smyth, of the UK consumer magazine Which? said: "This legislation will help people make healthier food choices.
"At long last people will be able to buy foods with the confidence that the health claims on the label have been checked."
Under the new rules, products will have to meet strict criteria to make certain claims.
For instance, products claming to be 'salt-free' or 'sodium-free' will be limited to no more than 0.005 grams of sodium or salt per 100 grams.
The new laws will apply to all food or drink products made or sold for human consumption within EU nations.
They will not cover claims made on cosmetics, medicine or pet food products.
The separate law on vitamins draws up an EU list of approved vitamin and mineral products that can be added to food, and criteria for setting minimum and maximum levels.
Products not on the EU list but still used in food, will have to be phased out over the next seven years.
The new rules ban vitamins or minerals to be added to fruit, vegetables or meat products, and alcohol drinks, with the exception of fortified tonic wine.