To stem the increasing incidence of non-communicable diseases (NCDs) and obesity, front-of-pack labels (FOPLs) have been developed since 1989. Whereas several countries have already adopted one voluntarily, the European Community wants to harmonize an FOPL system that will be mandatory for all member states. The purpose of this narrative review is to describe what could be achieved or not by FOPLs, and to discuss if there is enough evidence to establish whether such labels are effective in modifying purchasing behavior, in directing individual dietary patterns towards a healthy and sustainable diet, and in reformulating food products by the food industry. Non-directive FOPLs, which are still under study, appear to be informative and well-accepted by consumers even if they require a cognitive effort. Conversely, directive FOPLs are supported by several studies, but they are mostly conducted in simulated scenarios and/or performed as retrospective studies. Nevertheless, directive FOPLs are rated as an intuitive tool, and they have demonstrated a high capacity to help consumers rank food products as more or less healthy. In conclusion, directive and non-directive FOPLs convey different messages. No FOPL individually can be considered exhaustive in relation to all the objectives outlined in this narrative review, and therefore, the development of a model synthesizing both messages is advisable. Many questions remain open, such as the possibility of reformulating pre-packaged products, how to deal with traditional products, and the impact on the incidence of NCDs and obesity. In the light of the complexity of factors that condition consumption choices and health, none of the current FOPLs can be considered a health policy tool on its own. The possibility of development remains open, but as the state of the art, these tools do not seem to be able to achieve all the European Community goals together. We can speculate that they could meet these goals only if they are integrated into a multi-tiered, structured health policy intervention.

Background: Front-of-Pack Nutritional Labels are considered a useful tool to help consumers orient themselves in their food choices and direct their behavior toward a healthier diet. FOPNL development and use are part of a framework that includes cognitive, biological, hedonic and cultural aspects, able to affect consumers' eating and purchasing behavior. Aim: Given the complexity of the matter, the aim of this narrative review is to analyze the combination of different factors that drive food choices and eating behaviors and to highlight some aspects that are not fully studied. Methods: The authors conducted the research using a top-down approach at first, followed by a bottom-up approach; starting with general considerations about the purchasing process, gradually narrowing the discussion to a specific sub-population, and finally extending the discussion back to more general reasonings about the direction to adopt in future, or at least to evaluate, for effective communication. Results: Biases and attitudes toward food products were found to regularly interfere with buying behavior patterns, making it impossible to standardize an average consumer. This reflects in current research, increasing the complexity of the topic. All determinants influencing food choices are often assessed individually rather than in a synergistic and multidimensional context, while the purchasing scenario is characterized by multiple stimuli to which the consumer is subjected. FOPNLs’ impact on perceived healthiness has been studied in different conditions, but some population subgroups have not been sufficiently represented. In particular, the effect of FOPNLs on consumers suffering from eating disorders is understudied and needs further attention. Furthermore, some approaches can be compared to “negative nutrition” or “loss-framed communication”, putting nutrients out of context, emphasizing losses more than gains and risking promoting negative feelings in consumers. Conclusion: Due to the heterogeneity of studies, evidence on what works best in driving people to adopt lasting lifestyle changes is still mixed. Science communicators and policymakers should consider the possibility that a multi-component approach incorporating nutrition information and education may be a key strategy to promote consumers’ self-consciousness and to support them in their cognitive efforts toward a healthy and sustainable diet. Level of evidence: Level V, narrative review.

Summary: The food system significantly affects the environment through land use, emissions from livestock, deforestation, and food waste. Diet sustainability considers the environmental effects of food production, distribution, and consumption. Animal products emit more greenhouse gases than plant‐based foods, prompting a shift towards plant‐focused diets for reduced emissions. Sustainable diets, like the EAT‐Lancet model, prioritize plant‐based foods, adjusting for regional eating habits. These diets aim to be both environmentally friendly and conducive to human health, addressing concerns like obesity and chronic diseases. Obesity is a major global health challenge, and its complex relationship with food production and consumption patterns calls for sustainable solutions to reduce pressure on ecosystems and promote healthier lifestyles. Tackling obesity requires holistic strategies that address not only individual health but also the broader environmental impacts of food systems. A systematic review examined the link between plant‐based diets and obesity focusing on studies assessing Body Mass Index (BMI) and body fat assessment. Despite limited research, evidence suggests that adherence to a plant‐based diet, particularly a healthy one, is associated with lower obesity rates. More longitudinal and intervention studies are necessary for a stronger consensus on the matter.

As a team of scientists who believe that exchanging views is one of the prerequisites of the scientific method, we welcome the comments from Aguenaou H et al.