Front-of-pack labels help Singapore’s shoppers make healthy choices

Both the United Kingdom’s Multiple Traffic Lights (MTL) and France’s Nutri-Score (NS) front-of-pack labelling schemes improve diet quality, according to a recent Singapore study.

“Neither label was superior to each other in terms of modified Alternative Healthy Eating Index (AHEI)-2010 scores, but NS performed better than MTL in terms of average Nutri-Score. This should not be surprising given that the average Nutri-Score most closely tracks what consumers saw on the NS label,” said researchers.

Through an online grocery store, the researchers assessed the effects of the UK and France labels as compared to no-label controls. The study included 147 participants (mean age, 34.69±6.83 years; 68.83 percent female) who were exposed once to the three shopping conditions in a randomized fashion. The mean AHEI-2010 score in the control condition was 41.81 (95 percent CI, 40.71–42.92). [Nutrients 2019;doi:10.3390/nu11092236]

Both the MTL (estimated effect, 1.16±0.53; p<0.05) and the NS (estimated effect, 1.09±0.53; p<0.05) labelling schemes resulted in significant improvements in AHEI-2010 scores relative to the control. The difference between labels was not significant (estimated effect, –0.07±0.58).

When diet quality was assessed using Nutri-Score, the NS label remained significantly superior than the no-label controls (estimated effect, 0.33±0.09; p<0.01). NS also outperformed MTL (estimated effect, 0.31±0;09; p<0.01), which, in turn, had no statistical edge over the control (estimated effect, 0.02±0.08).

However, the MTL labelling scheme had a stronger effect on the overall number of calories, cutting It by 19.75 kcal/serving (p=0.01). Total fat and protein similarly decreased in the MTL shopping condition, by respective values of 1.03 (p=0.03) and 0.83 (p=0.01) g/serving. The NS scheme, in comparison, was only able to reduce total saturated fat per order (29.29 g; p=0.01) relative to the no-label control.

Mood, education, income level and hunger all showed no possible moderating effect on the relationship between labelling and diet quality.

“Front-of-pack labelling has been identified by the Singapore government as one of four promising strategies to tackle nutrition-related diseases,” said the researchers. “Our results show that both the MTL and NS labelling scheme employed led to statistically significant improvements in diet quality relative to no-labelling.”

The overall pattern of effects was consistent even when analysis was restricted to food items or beverages alone.

“These results provide support for implementation of either label if the goal is to improve overall diet quality as assessed via modified AHEI-2010 and average Nutri-Score,” the researchers noted.

However, because the MTL allows consumers to see the level of specific nutrients more clearly on the packaging, it may be the better option if the ultimate objective is to reduce the intake of calories, fats or sugars, or to influence a particular public health measure, such as the rates of obesity. On the other hand, the NS labelling scheme may be more effective if overall diet quality is the target of interest.

“Future studies should test these labels over repeated purchases and in different shopping venues, including on-line and in-person grocery and convenience stores, and with a broader subset of the population,” in order to yield more robust and more generalizable recommendations, the researchers added,