1. Introduction
The epidemic of overweight and obese individuals presents a major challenge to chronic-disease prevention and to health over the course of life worldwide. Fuelled by increasingly sedentary lifestyles and a nutritional transition towards processed foods and high-calorie diets, many countries have witnessed the prevalence of obesity amongst its citizens double, even triple [
1]. One key mechanism that policymakers have presented to encourage healthier eating is the provision of information on food packages via nutritional labels [
2], such as nutritional claims (NCs) and health claims (HCs) [
3]. Both types of claims are an attempt by the European Union (EU) Regulation (EC) No. 1924/2006, with the aim to help consumers make well-informed choices [
4,
5] at a glance [
6]. However, NCs and HCs are credence attributes. This type of attributes is neither directly observable by consumers before purchase, nor can it be experienced after purchase [
7,
8]. Therefore, to guarantee trustworthy information to consumers the European Food Safety Authority (EFSA) requires that NCs and HCs in food products be based only on scientific evidence [
9]. Since the introduction of the EU regulations, the agro-food industry has increasingly made efforts in the innovation processes to obtain healthier products by reducing saturated fats, sugars, and salt, while the retail sector has increased considerably the presence of processed products with NCs and HCs in the EU markets. In 2015 about 85% of all packaged food products in Europe were sold with NCs [
10,
11] with Spain ranking as second, after the UK [
10]. Regarding the type of claims used in the Spanish market, Cuevas (2012) reported that the NCs with the highest presence pertain to food products that are: rich in fibre (47.5%), without added sugar (41%), free of saturated fat (41%), low in calories (39%), rich in whole grains (34%), rich in vitamins and minerals (26%), low in salt or salt-free (25%), and rich in omega-3 fatty acids (22%) [
12]. Similarly, Royo-Bordonada et al. (2016) who examined the availability of food with NCs and HCs in Spanish television advertisements over a seven-day period identified 169 food products, of which 28.5% belong to the dairy group and 60.9% to the non-core or miscellaneous category. A total of 53.3% of products contain NCs, and 26.6% contain HCs. Low-fat dairy products are the category with the highest percentage of NCs and HCs [
13]. Finally, a more recent study by Lopez-Gálan and de-Magistris (2017) on the presence of NCs in the Spanish market found that, out of 4568 product types, about 900 contain NCs. The most frequent nutrients found are related to the fat (42%), sugar (32%), dietary fibre (20%), and salt (6%) contents. The results from these studies demonstrate that Spanish consumers have access to food alternatives with NCs and HCs, however it has been reported that only a very small percentage of consumers purchase them [
14].
Beside the availability and exposure to the market of foods with NCs and HCs, other factors that affect the purchase of food with these claims are several attitudinal and cognitive characteristics, which are related to nutritional and health knowledge, understanding, interest in healthy eating, and socio-demographic characteristics (see [
15,
16] for an overview). Understanding the NCs and HCs provided on the FOP implies that consumers recognise and know what each nutrient term and measurement unit means. It also assumes that they understand the relationships between the different nutrients and the role of each nutrient in the body [
17]. In this regard, Prieto-Castillo et al. (2015) report that over half of the participants in Madrid (52.4%) stated to have a full understanding of nutrition labels. The highest percentage was found in consumers over 65 years old (63.6%), retired (62.5%), living alone (62.1%), and with a high level of education (61.8%). Higher education was also found to be positively correlated with information search and self-perceived understanding of NCs in another Spanish study [
11]. Regarding knowledge towards foods with nutrition labels, previous research noted that consumers’ knowledge of the nutritional properties of food products play a role in the importance associated with the labelled claims, as it may increase the perceived benefits of the product [
18,
19]. Two Spanish studies [
20,
21] indicated that a higher level of nutritional knowledge is linked to healthy individuals, with high income, and households with children who are more motivated to search for nutrition information. Hence, Spanish consumers with greater knowledge of nutrition information are more likely to use nutritional labels [
21]. Finally, the need for information about food, diet and health is driven by most importantly, consumers’ use and interest in healthy eating [
22]. One may have sufficient knowledge of the nutritional properties of the food product and understand the labels, but not the interest in healthy eating and use of NCs and HCs in the decision-making. Hence, consumers’ use and interest in healthy eating is the attitudinal characteristic studied in this research as these type of consumers tend to be more engaged in health-promoting behaviours [
23].
In overall, products with NCs and HCs have been considered to be part of a healthy diet [
23], and the appeal of HCs is positively linked to the interest in healthy eating [
24]. However, research regarding preferences and interest in healthy eating of food with NCs and HCs in Spain is limited and the results are mixed. Specifically, Barreiro-Hurle et al. (2010) report that although individuals use nutrition-facts panels and NCs, most consumers use only one of these claims (33%) and of these, the majority pay no attention and show a low interest in using NCs (68%) [
20]. This is also consistent with the results of Prieto-Castillo et al. (2015), who found that only a small percentage of individuals in Spain were interested to use NCs [
11]. Lastly, López-Galán and de-Magistris (2019) who explored the effects of emotional eating in the purchase behaviour, found that emotional eating had a negative impact on the purchase behaviour of food with NCs [
25]. On the contrary, recent research on consumer preferences for NCs and HCs in Spain suggest that preferences are heterogeneous. In particular, de-Magistris et al. (2016) assessed the influence of body image on consumer preferences for potato chips carrying NCs among obese and normal-weight participants. Their findings indicated that obese people with body-image dissatisfaction were willing to pay more for healthier chips compared to normal-weight participants with the same problem [
26]. Finally, Jurado and Gracia (2017) examined Spanish consumer evaluation of NCs (i.e., high in fibre and reduced saturated fat) on breakfast biscuits. They report that consumers positively valued both NCs, and premium prices may be attached to targeting either of two subpopulation segments (low-saturated-fat seekers and high-fibre seekers) [
27]. In our view, these studies are important. Nevertheless, we believe that the full advantage of using multiple types of NCs and HCs was not taken. In overall, the results from this literature suggest that our understanding of Spanish consumers’ sensitivity towards NCs and HCs is still fragmented and should be further investigated.
Given the aforementioned, the purpose of this research is to examine the relationship between choice behaviour, attitudes, and socio-demographic characteristics, and evaluate the effectiveness of consumer characteristics in predicting Spanish consumers’ choice of products with NCs and HCs. To achieve these objectives, we used a discrete choice experiment (DCE) on plain yoghurts. To find out whether there is a segment of Spanish consumers responsive to NCs and HCs and how it differs from the rest of population, we applied the latent class (LC) approach which permits an analysis of determinants of consumer choices, taking into account the heterogeneity that may exist between different segments.
This study focuses on NCs and HCs because they are a simpler way of presenting information compared to nutritional tables. They do not list the amount of a nutrient, but instead summarise the information for a specific nutrient and communicate it to consumers in simple, easy-to-process language (e.g., fat-free). We chose yoghurt as a product of reference, as it has been recommended as part of a healthy diet in many countries [
28], and it contains the most NCs and HCs among all the food products in Spain (From a market analysis on various food products present in different hypermarkets and supermarkets in Spain, it is the product that carries the most NCs and HCs). We chose Spain as the location of research due to the high number of NCs and HCs available in the Spanish market [
10,
27]. While the existing literature provides a wealth of insights into attitudinal and cognitive characteristics such as nutritional and health knowledge, and understanding of food products with NCs and HCs, to the best of our knowledge, this is the first study that analyses consumer heterogeneity in preferences for multiple NCs and HCs on the front of pack (FOP) by identifying Spanish consumer segments. The characterisation of consumers based on categories would allow food companies and public authorities to tailor strategies to promote healthy food choices.
4. Discussion
Overall, the results indicate that consumers positively value both NCs and HCs on yoghurt FOPs. This is consistent with the general literature review findings that consumers are willing to pay premium prices for these type of claims [
15,
17,
20,
26,
27,
61,
62]. In addition, this result aligns with previous research, which suggests that individuals prefer dairy products with HCs and NCs rather than similar ones without these claims [
18,
63,
64]. In this study, however, we identified three segments with heterogeneous preferences across consumers: HC-oriented (34.7% of participants), NC- and HC-oriented (50.0%), and indifferent (14.9%).
In terms of gender, our results reveal the presence of a gender dimension in the preference for yoghurts with NCs and HCs, highlighting that women (HC-oriented) display higher levels of acceptance for fat-free yoghurts and yoghurts with added calcium than men do (NC- and HC-oriented). This is consistent with Johansen et al.’s (2011) study, which found more positive attitudes towards low-fat yoghurts among Danish, Norwegian, and U.S. (Californian) female consumers compared to male shoppers [
65]. In the same line, our results agree with Wardle et al. (2004), who report that women are more health-conscious than men and that the former mainly prefer fat-free or reduced-fat dairy products because they support weight control [
66]. Concerning the calcium content, our results illustrate that older women perceive higher utility for calcium-related HCs (‘calcium is necessary for maintaining bones under normal conditions’ and ‘calcium contributes to normal muscle function’) present on yoghurt packages (HC-oriented). This result is consistent with the previous research [
18,
67] findings that female consumers are more willing to try yoghurts with added calcium. One reason that women prefer functional dairy products that are rich in calcium and promote bone health is due to their higher risk of developing osteoporosis [
63,
67,
68].
With respect to age differences among segments, we found that HC-oriented as well as NC- and HC-oriented consumers who are older than 55 years attach higher utilities to both types of claims compared to younger members of the indifferent group (18 to 34 years old). This result agrees with previous studies, which have reported that being older is positively associated with a higher interest in dairy products that promote disease risk-reduction properties such as lowering cholesterol [
63,
69,
70]. In addition, older consumers have been exposed for a longer period of time to food products with functional properties, hence, they are more knowledgeable and familiar with functional dairy products and their effects on health [
69,
70,
71].
Besides age, another interesting finding is one of homogeneity: the majority of people of normal body weight across all segments evaluate taste as the most important attribute. Having a normal body weight and no health problems (
Table 3) also explains the behaviour of consuming tasty food that may raise cholesterol. Hence, regarding preferences in taste, the results suggest that participants across all segments are highly sensitive to the taste of food, and they do not compromise on this aspect for the sake of health. This observation is even stronger among the participants who are indifferent towards and disinterested in purchasing yoghurts with NCs and HCs. This result is consistent with ones reported by Verbeke (2006), who found that consumers who purchase functional foods in Belgium are also not ready to compromise taste for health [
72].
The results regarding NC and HC preferences suggest that, overall, consumers from all segments prefer yoghurts with these claims compared to those without. However, when it comes to comparing higher utilities between NCs versus HCs, the study demonstrates that the latter carry higher utility. In other words, presenting both types of claims together on yoghurt packages generates higher preferences. This finding differs from that of Barreiro et al. (2010b), who obtained negative utility from the combination of NCs and HCs on the package of a less healthy product (pork frankfurter sausage) [
62]. However, our results are consistent with other studies that have explored consumer preferences for functional food products. Among the many claims available on the market, shoppers generally prefer HCs to NCs [
63,
73,
74,
75].
These results have practical implications for food companies and public authorities. Presenting both types of claims on the package can be used as a differentiation strategy by food companies. For the operators of the agri-food sector, the diffusion of foods with NCs and HCs can represent an opportunity to grab by means of implementing marketing strategies aimed at the different consumer segments. Policymakers will have to introduce HCs that are highly valued by consumers (e.g.,
Hca_sug and
Hca_cal) but are not yet available on the market for yoghurts. Although the level of education is increasing and people today are more informed than ever before, there is still a segment of consumers (i.e., young people without any health problems) who are indifferent towards consuming products with NCs and HCs, and who do not avoid foods that may raise cholesterol. Hence, in terms of public health nutrition aspects (We thank an anonymous reviewer for pointing out this possibility), it may be constructive to use behavioural insights rather than device new policies. In this context it is worthwhile to introduce healthier-eating programmes and reinforce the consumption of healthy diets (e.g., the Mediterranean diet) to young Spanish people and combine it with food products with NCs and HCs. Five decades ago, the Spanish diet was a typical example of the Mediterranean diet, however, lately, Spanish consumers have moved away from that pattern [
76]. Previous research, among others, the PREvention con DIeta MEDiterranea (PREDIMED) suggested that better adherence to the Mediterranean diet pattern together with a regular physical activity exerts a greater impact in lowering obesity and all-cause mortality [
77,
78,
79,
80,
81]. With respect to the dairy products and precisely yoghurts, which form part of Mediterranean diet, it is well demonstrated that whole-fat and low-fat yoghurt consumption is associated with a reduced risk of general obesity [
77,
82] and also abdominal obesity [
83,
84]. Therefore, public expenditure could encourage the promotion of typical Mediterranean products with NCs and HCs in high schools and colleges. The extensive use of TV for educational purposes to reach children with an attractive food program, linking healthy food habits with sports celebrities and leisure offers, as well as to search for more accurate the appropriate combination of healthy food based on the ingredients of the Mediterranean diet is also another form of educating consumers. Finally, the popularity, acceptability, and generally perceived healthy image of yoghurt all make it an ideal snack or meal accompaniment in many cultures. The consumption of yoghurt as healthy food can be promoted especially among adolescents whose consumption of milk is low, hence, yoghurt can be considered as a milk substitute. Yoghurt should not replace fruit as a typical dessert of the Mediterranean diet but public health interventions should promote its consumption on health and educational campaigns as it plays a role in the prevention of weight gain and overweight/obesity [
82].
Finally, this study has some limitations and further research opportunities. First, due to limited funding, it was conducted in Spain. Hence, it should be replicated in other countries to provide more evidence. Second, future research using choice experiments should be developed, not only in laboratory conditions but also in a supermarket with real products to test consumer preferences and decision making in different contexts. In our study, we used schematic choice cards as opposed to actual product packaging, which would have been more realistic (see for example [
85]). In addition, hypothetical choice experiments do not use actual purchase and monetary risk, which is still a disadvantage compared to real choice experiments. Therefore, care should be taken in fully translating our results to real-life choice situations. Conducting real choice experiment with real products and real economic incentives will increase realism and avoid the hypothetical bias, which is a limitation in our research. Third, the FOP of a food product generally includes not only the NCs and HCs but also other extrinsic information (e.g., price, brand name, ingredients list, symbols, etc.). Therefore, further studies should include packages carrying other information cues in addition to NCs and HCs to evaluate the impact of these attributes in a choice environment. Finally, in terms of climate impacts (We thank an anonymous reviewer for pointing out this possibility) (e.g., greenhouse gas emissions, blue water footprint, land use etc.) associated with shifts to diets and dietary recommendations, it is important to point out that yoghurt is a dairy product, which presents a high carbon footprint per caloric intake. The previous research of Heller and Keoleian’s suggested that following a diet reduced in calories (estimations based on consumption rather than intake) results in a 1% decrease in diet-related greenhouse gas emissions [
86]. In addition, Meier and Christen’s found that following an iso-Caloric shift to the German Nutrition Society Official food-based dietary recommendation could reduce energy use by 7%, blue water use by 26%, emissions by 11%, and land use by 15% [
87]. Lastly, Vanham et al. (2013) determined that shifting to the same German dietary guidelines within the EU and Croatia while also accounting for a reduction in caloric intake reduces the diet-related blue water footprints by 18% [
88]. Taking into account these studies, it would be very interesting to investigate in the future whether the Spanish consumer who attaches more importance to NCs and HCs on dairy products contribute or not to climate impacts such as reducing energy use, emissions, and blue water footprint.