Governments in several European Union (EU) countries have begun recommending that food producers add health scores to their packaging.
Researchers now say proven health benefits mean the labelling system should be mandatory.
Head to a supermarket in many European countries and you'll find a growing number of food products have started slapping traffic light ratings on their packaging to clearly show how healthy they are.
Muesli and natural yoghurt?
Green with score "A".
Salted crisps and sugar-coated cereals?
Watch out, these often have an orange "D" or red "E".
The simple traffic light labels, adopted by many manufacturers in France, Germany and Spain, is a voluntary measure, but recommended by many governments in Western European countries.
Researchers have now found the the so-called Nutri-Score label contributes to a healthier diet for consumers by helping them to easily spot which foods are sugary.
Scientists at the German University of Göttingen reported in study in the scientific journal PLOS One that the voluntary product label in Germany helps counteract misleading marketing claims about sugar.
Companies often give the impression that products are healthier than they actually are (with statements such as "no added sugar" or "30% less sugar"), writes the team led by Dr Kristin Jürkenbeck from the university's Chair of Marketing for Food and Agricultural Products.
"Such nutrition claims can lead to false assumptions about the healthiness of foods and can lead to health-halo effects," the authors write.
"As a result, food products can be perceived as healthy, even though they are not."
However, the Nutri-Score helps consumers to recognise that these misleading statements don't mean their sugar intake is healthy.
The Nutri-Score evaluates the amount of sugar, fat, salt, fibre, protein or fruit and vegetable content per 100 grammes.
The total value formed from this is shown on a five-point scale: from "A" on a dark green field for the most favourable balance, to a yellow "C" and a red "E" for the least favourable.
For the study, participants were shown three different commercial-like products online: a ready-to-drink cappuccino, a chocolate muesli and an oat drink.
These were each printed differently with either the Nutri-Score label or sugar messages as used by companies.
The participants rated products with company claims of reduced sugar content as healthier than they actually were.
This was not the case with the food products printed with the Nutri-Score, some of which were also printed with the reduced sugar claims.
High sugar consumption can increase the risk of obesity and other diseases, the authors emphasise.
They therefore call for restrictions on misleading sugar claims and say if companies continue to make such claims on their products, the Nutri-Score should become mandatory.
The product label, which is similar to the energy rating labels on household appliance sold in the EU, is increasingly being used in various European countries and has become voluntary in France, Belgium, Spain and Germany in recent years. – By Maurice Arndt/dpa