I suppose the political debate within the European Union about introducing a new food labeling system has already been harshly fought and lost, but it probably seems still worthwhile to introduce parts of the discussion in the information graphics community. (however, some sources still give it a small chance of success)
The "Traffic Light Labeling" or "Traffic-Light Nutritional Signposting" uses red, amber and green signals to show consumers, at-a-glance, whether a food product is high, medium or low in fat, saturated fat, sugars and salt. The traffic-light labels is specifically designed to enable quick comparisons between similar products, in an attempt to encourage consumers to make healthier food choices by choosing more products with green or amber lights than red.
The currently used food labeling provides the percentage guideline daily amounts (%GDAs) of a specific food product. It is claimed this %GDAs scheme creates a number of barriers for making healthy choices: first, they may suggest to the consumer that GDAs are daily targets to be aimed at, whereas in fact they are limits not to be exceeded. Second, the %GDA numbers provide values 'per portion' rather than per 100g or 100ml. In addition, brands often differ in their definition of what a 'portion' exactly constitutes. Lastly, the percentage amounts apply only to people of 'average' build', excluding an increasing amount of consumers.
In addition, a recent scientific study has shown that traffic light labels work much better than %GDA labels (or a mix of the two) across all socio-economic groups. This means that the traffic light scheme is less likely to widen dietary and health inequalities by only being useful to the most numerate or literate consumers.
People against the system (and most, if not all, major food brands) argue that the traffic lights cover a too broad numerical range to be meaningful. For instance, a single soup spoon of both full-fat spread or low-fat spread would would be both colored red. Secondly, some foods such as olive oil and walnuts would be displayed as red lights in spite of their health-giving qualities. In other words, if a consumer stucks to a green lights diet only, she would actually not be eating a balanced diet, as one needs a certain amount of carbohydrate and fat.
Taken these arguments into account, and from an information graphics point of view, is the traffic light metaphor the right way to communicate nutritional information to people?
. McDonalds Menu Charts
. Nutrition Data Visualization
. Food Measuring Plate
. How Does 200 Calories Look Like?
. Cheerios Graph Critique
. What the World Eats
. How Much Sugar is in Your Food?
. Eat Local Advertisement
. Beer Consumption per Country
. How to Feed the World