One common strategy for governments to tackle the non-communicable disease (NCD) epidemic is front-of-package (FOP) nutrition labeling. The Kingdom of Saudi Arabia (KSA) is considering implementing a new FOP label that is based on either France's Nutri-Score (NS), which labels all foods (A = healthiest to E = least healthy) based on overall nutritional quality, or the Chilean warning label (WL) approach, which identifies foods to avoid based on select nutritional characteristics. Using a fully functional online grocery store, this study aimed to test these two promising FOP strategies by randomizing 656 KSA adults into one of the three versions of the store to complete a hypothetical grocery shop: no-label (control), NS, and WL. The NS was modified with a sugar percentage tag given that reducing sugar consumption is one of KSA's public health goals. We found that both modified NS labels and Chilean warning labels positively influenced food and beverage choices among KSA participants, but there were differential effects across the two labels. Relative to the control, NS improved the overall diet quality of the shopping baskets, measured by the weighted (by the number of servings) average NS point (ranging from 0, least healthy, to 55, healthiest), by 2.5 points [95% CI: 1.7, 3.4; p < 0.001], whereas results for WL were not statistically significant (0.6 points [95% CI: -0.2,1.5]). With respect to each nutritional attribute, we found that NS reduced sugar intake per serving, whereas WL was effective at decreasing energy and saturated fat intake per serving from food and beverages purchased. Our results suggest that the NS approach that identifies the healthiness of all foods using a holistic approach appears preferable if the purpose of the label is to improve overall diet quality as opposed to addressing select nutrients to avoid.
Keywords: Chilean warning labels; Nutri-Score; diet quality; front-of-pack labeling; online grocery shopping.