FOP labels are designed to help consumers choose healthier foods and drinks. This study compared how well five different FOP labels helped Brazilian consumers make a healthier choice between two food or drink products. It showed that the Hybrid label and the ABIA label performed best under the tested conditions. Both labels provide nutritional information per serving as well as a concise interpretation using colours (i.e. traffic light or red light only).
Most of the other studies that investigated how well different FOP labels helped consumers make a healthier choice between products, compared products within the same food category and with the same serving size, but with marked differences in nutritional profiles. These studies often found that simple interpretative labels such as Nutri-Score or warning labels were effective in helping consumers make a healthier choice [24–27]. This makes sense, because when a label clearly distinguishes between products (e.g. different score, colour or with or without a warning label), the consumer can easily make a choice. However, this does not reflect the complexity consumers face when shopping as this clear distinction does not always exist. Our research showed that when labels do not clearly distinguish between two products, or when products from different product categories or with different serving sizes are compared, these simple labels do not help the consumers to make an informed choice.
Many factors influence how consumers process information on a FOP label and how deeply this information is processed . Consumers may only glance at the FOP label, process partial information or process the FOP label in depth. For example, the level of nutritional knowledge influences the type of information the consumer processes. Knowledgeable consumers are more likely to use the more complex nutrient information on complex labels, while a less knowledgeable consumer may look for calorie and color-coded information. Average consumers are more likely to process the information on the FOP label in depth. Under time pressure consumers will only quickly inspect the information on the FOP label and not process all available information . Health-motivated consumers may also look more actively for nutritional information, while hedonically-motivated consumers may not look at nutritional information, but more at brand names . So, depending on the situation, different types of FOP labels can be the most effective.
Our study showed that simple summary labels are effective when there is a clear distinction between products, but if a quick decision cannot be made, consumers will consider the nutritional information on the FOP label, when available. In those cases, interpretative labels that provide nutritional information to the consumer better assist the consumer in making an informed choice. This study showed that, even when the colours on the Hybrid and ABIA labels did not differ between products, participants could choose the healthier option based on the nutritional information presented on these labels. This suggests that the nutritional information facilitates the comparison of the nutritional content of the products, allowing the consumer to make a healthier choice. The two warning labels, i.e. IdeC and GGALIii NP were in most cases not sensitive enough to help the consumer distinguish products based on healthiness. They did not outperform the control group. Both the Idec and GGALIii labels use very strict nutrient profiles and therefore most products bear the logo , making them less sensitive to distinguish products. In addition, these labels are also very simplistic and do not include additional nutritional information that can help the consumer make an informed decision where the number of sugars, saturated fats and sodium warning labels does not differ between two foods.
When labels on two different products are the same, respondents interpret this as if products are equally healthy, or respondents base their decision on other information they have about the product (e.g. packaging, type of product, claims on product, presence of other ingredients, knowledge of the brand). For example, the vegetable-oil based spread used in this study contained less saturated fat and sodium than the presented butter, so it is nutritionally, the healthier choice. However, Brazilian Dietary guidelines promote butter consumption, not vegetable-oil based spreads. Butter can therefore be seen as more natural and healthier than vegetable-oil based spreads in Brazil and this is also reflected in the results. When the FOP labels indicated that the vegetable-oil based spread was the healthier choice, most respondents chose that product. However, if no label was shown, or if the labels on butter and vegetable-oil based spreads did not differ (in case of IdeC and GGALIii NP), more than 40% of participants chose butter as the healthier option.
A recent review of FOP schemes conducted by the European Commission concluded that FOP schemes providing nutritional information per 100 g were better understood than portion-based schemes . However, more than 90% of the food categories in Brazil have regulated serving sizes less than 100 g / 100 ml. When a nutrient profile is standard applied in 100 g or 100 mL, distorted comparisons are generated. For products consumed in serving sizes < 100 g or ml, the amount of nutrients to calculate the FOP label is overestimated, while for products consumed in portions of > 100 g/ml it is underestimated. As a result, some products with small serving sizes will unfairly receive a warning label, while some products with large serving sizes that are high in nutrients of concern receive no warning label. For example, in this study, two lasagnas with a 400 g serving size were compared. According to the nutritional profile criteria defined by GGALIii, based on 100 g, neither of the two products would receive a warning label, and with Nutri-Score both lasagnas would receive a score of B. These two FOP labels would thus suggest that products are healthy, despite the relatively high content of saturated fat and sodium per serving as % GDA.
While the GGALIii NP and IdeC warning labels were the least successful in helping participants make the healthier food choice, the labels were considered by the respondents to be as useful as the other FOP labels. It is important to note that the respondents did not receive any feedback on how well they did. So they were not aware of the correct answer and how often they correctly identified the healthier option or mistakenly assumed there was no difference. One could speculate that if they got this feedback, ratings of usefulness would be lower. In any case, the ratings show that any FOP label that could help the consumer make an informed choice is considered useful by consumers. For research purposes, asking this question without providing feedback to the participants does not seem relevant. Feedback from the participants suggests that simple FOP labels that use bright colours and contain nutritional information in simple language, are liked.
Grunert et al hypothesized that consumers’ liking for FOP labels is guided by three considerations: 1) consumers like simplicity, 2) when provided with simplified information consumers still want to know what it stands for and how the simplified message (e.g. warning- or health logo) has been derived, and 3) nutrition information can create a consumer resistance when they feel pushed to make choices that they do not want to take .
This is also confirmed by a recent study conducted by Talati et al  which investigated consumer perception of five FOP labels, i.e Health Star Rating, MTL, Nutri-Score, RI and a warning label. The coloured FOP labels MTL and Nutri-Score stood out and were most liked by consumers in all countries. Although the most simplified FOP labels, Nutri-Score and warning labels, were easy to understand, they were perceived as providing insufficient information and the least trusted. The RI label was perceived as the most confusing but scored high on trust. Overall, the MTL label, which combines nutrient-specific information and a summary interpretation using colour, was most liked and trusted in this study.
A strength of the current study was that it really tested the robustness of five FOP labels that differed not only in visual expression and the amount of information provided, but also in the underlying nutrient profile. Unlike other studies that mostly tested products within the same food category and with the same serving size, this study was designed to compare how well these five FOP labels enabled consumers to choose between products that differ in nutritional composition, serving size and/or food category as consumers face in real life. Another strength is that a control group has been included and that the effectiveness of the FOP labels in helping the consumer to choose the healthier product could therefore be compared with a reference group that was not given a FOP label. This provides insight into whether the presence of a specific FOP label is of added value for a consumer when making an informed choice.
Participants were also asked to select the healthier product. This demonstrates how effective the FOP label is in helping the consumer make a choice and whether it fits its purpose. In other studies consumers were asked which product they would buy [31–35], but this may be influenced by factors such as familiarity and liking of the product and the cost of the product . Other studies only asked which FOP label is preferred [30, 36]. As demonstrated by our study, all FOP labels were rated as very useful, irrespective of their efficacy in helping the consumer choose the healthier option. Only asking for preference is thus not very useful.
This study also has some limitations. The participants were a representative sample of the Brazilian population. Therefore, we also included participants with a lower education level, who may have had difficulty understanding the information on the FOP labels. However, socio-economic status and level of education were similar between the six FOP label groups and therefore we did not expect this to affect the outcomes of the study. This was confirmed by statistical subgroup analyses that showed that participants who correctly identified the healthier options, did not differ in education level or income. Another limitation is that we did not ask participants if they were colour-blind. Thus, it is possible that participants with colour-blindness were included, which may have adversely affected the ability to understand the colour-coded labels. However, none of the participants who were shown the Abia or Nutri-Score labels, voluntarily reported to be colour-blind and thus unable to interpret the labels.
The FOP labels we tested in this online survey were selected because they were under consideration by Anvisa, the National Health Surveillance Agency of Brazil, at the time we designed this study. Anvisa proposed in its preliminary report on the regulatory impact analysis on nutrition labelling  to focus only on the three nutrients of concern, sugar, saturated fat and sodium. We therefore decided to only use the content of these three nutrients to inform the different FOP labels (with exception of Nutri-Score). Focusing on just these three nutrients of concern is a limitation to assessing the healthiness of a product.
Brazilian regulations do not require the sugar content of food products to be stated on the packaging. For some of the products used in this study (ice creams, frozen meals, dairy alternative drink, sweet snacks), we had to estimate the sugar content. These estimates were unlikely to deviate very much from the actual sugar content and were used for all FOP labels.
This study was conducted online using pictures of actual products. It does therefore not reflect a real-life situation in which participants can examine packaging and other information, such as the nutrition table on the back, to make an informed choice. Finkelstein et al  attempted to mimic a real-life situation by asking the participants (n = 147) to purchase their weekly groceries in an online grocery store with 3343 foods and 832 beverages. Participants only had access to back-of-pack Nutrition Information Tables or were also shown an MTL label or Nutri-Score label. Both the MTL and Nutri-Score FOP labels improved the dietary quality of the purchases as compared to the control group. The Nutri-Score label performed best in improving overall diet quality, but unlike Nutri-Score, the MTL label reduced calories. Thus, FOP labels had added value when purchasing products, even in the presence of a Nutrition Information Table.