Family affluence and cultural capital as indicators of social inequalities in adolescent’s eating behaviours: a population-based survey

Among the large number of young people in Norway who not does follow national dietary guidelines [1], those from families with low socio-economic status (SES) are at particular risk. Their diet is likely to contain less fruit and vegetables [2, 3] and more sweets and soft drinks [4, 5], and the frequency of their meals is likely to be less regular [6], than for their counterparts from families with high SES. Socio-economic variations in diet are of concern because they are associated with a range of health conditions and therefore represent pathways by which socio-economic inequalities lead to inequalities in health status [7]. Adolescents, in particular, are a group to target strategically when aiming to reduce observed disparities in food habits from a global public health perspective. Adolescence is the most important period for establishing food preferences and habits that will be maintained into adulthood [6, 8], and it is the transition period during which familial disadvantages are forming the basis for young people’s SES as independent adults [9, 10].

Relatively little is known about the mechanisms underlying socio-economic disparities in eating habits or how to offset inequalities among young people. The Nordic public health service has accordingly acknowledged the need for further research on socio-economic mechanisms determining variations in adolescents’ diet [11]. Identifying distinct aetiological pathways between socio-economic status and eating habits would contribute valuable knowledge to policymakers and others who need to design interventions that effectively reduce social inequalities in diet.

Dietary inequality, via SES inequality, may involve several mechanisms. Education, occupation and income are most frequently used as indicators to explain variations in SES [3]. Education may influence food habits by facilitating or constraining reading and comprehension of nutritional information and compliance with nutritional recommendations as well as influence values attached to healthy eating [12, 13]. Occupation may affect diet through role modelling in work-based relations and social networks [14, 15]. Income may reflect the availability of economic and material resources, which could directly determine dietary quality by making healthy food more affordable and readily accessible to those with higher incomes. Also cultural capital has been linked to health inequalities [16, 17]. Cultural capital can be broadly defined as people’s symbolic and informational resources [18]. These resources, which are varying across the social classes and status groups [19], have been suggested to influence health behaviour through the operational skills, knowledge, health considerations and norms acquired through education and socialization [16].

Each of the above approaches contributes to a complex understanding of the SES construct. However, some researchers seem to assume that different SES indicators reflect the same underlying information and can therefore be used interchangeably [20]. This assumption is reflected in studies using only one indicator even when several are available, as well as in studies making indices without adjusting for the unmeasured effect of one indicator on another [21, 22]. The assumption that different indicators can be used as proxies for the same phenomenon is challenged by the results of studies that examine correlations between different SES indicators. Typically, correlations between education, occupation and income are weak to moderate (magnitude 0.3–0.6) in developed countries [23, 24]. This finding suggests some shared associations but also, more importantly, highlights the unique contribution of each indicator. It also supports the view that the different indicators are conceptually distinct, and that their influences on eating habits are transmitted through social processes. Additionally, the relevance of a specific indicator might differ between subgroups of the population, such as between adults and adolescents. In a study of a US sample, Krieger et al. [25] found that different SES indicators differed between gender, ages and different ethnicities. This underscores the need for specific knowledge in order to target intervention approaches according to age, gender and ethnicity. Moreover, one dimension of SES may be of particular relevance in promoting healthy behaviours such as consuming fruits and vegetables, while another dimension may play a significant role in promoting health-compromising behaviours such as consuming food rich in fat and sugar. Differential association can be viewed as a methodological issue but is also strongly relevant to operating mechanisms, since differential associations across SES indicators may signal specificity in the processes influencing eating behaviours [20, 26].

Further complicating the issue of specificity of indicators is the difficulty adolescents have in reporting their parents’ education and occupation. Even more serious are the systematic missing data from adolescent respondents from families with low SES, who frequently experience difficulties in reporting parental SES [27]. As a supplement to conventional indicators, the above limitations call for proxy indicators tailored to the socio-economic circumstances of adolescent populations. Against this background, SES-based differences in adolescents’ consumption of fruit, vegetables, sweets and sugary soft drinks and in meal frequency were in the current study investigated among Norwegian students at junior high school (age 11, 13 and 15) and senior high school (age 16) using two different dimensions of SES: Material capital measured by the Family Affluence Scale (FAS) [28], and cultural capital measured by number of books in the household. The effect of material resources is evaluated as an important determinant of food choices in adult populations, but little is known about how such resources affect eating patterns in adolescent populations. The economic situation of families in Nordic countries is of particular importance for policymakers trying to facilitate healthy food choices by adolescents, because fruit and vegetables are quite expensive. The FAS taps young people’s absolute socio-economic status based on material markers, provides an alternative to the more traditional social class [27, 28], and is conceptually related to common consumption indices of material deprivation [29] and home affluence [27]. Cultural capital has thus far been rarely studied as a dimension of SES in relation to inequalities in diet [17, 30]. In the present study, Bourdieu’s [31] concepts of cultural capital and habitus are used as an approach to the formation of taste and consumption, which, among other initiatives, is expected to influence young people’s attitudes towards healthy eating. The concept of cultural capital refers to social abilities and competence for action, including perceptions, behavioural norms and operational skills that are needed to deal effectively with health issues on an everyday basis [16]. Habitus consists of previously established categories of perception that create an inner felt understanding of what is valuable and what is not [32]. According to Bourdieu [31], books represent an objectivized form of cultural capital, and number of books in the family has previously been used as an indicator of cultural capital in several inequality studies among children and adolescents [32‐38]. Number of books in the household may be seen to act as an indicator of the underlying cultural capital [32] and is likely to be positively associated with education.

To our knowledge, cultural capital as a determinant of eating habits among adolescents has never been studied in a national, representative sample. Our aim was to evaluate the predictive values of material capital (family affluence) and cultural capital as determinants of eating habits among adolescents in Norway.

In this study, data from participants in the Norwegian study of the World Health Organization (WHO) cross-national HBSC study (2005/2006) were used. The sample was selected using a stratified standard cluster sampling procedure to ensure national representativeness [39]. The primary sampling unit was the school class, with one participating class per age group. The school was used if school class information was not available. The sample was randomly selected using a standard cluster sampling procedure based on a geographical stratified list and sequentially selection from a randomized starting point. Of the 551 invited schools 378 chose to participate in the study. Data were collected from 3,318 boys and 3,129 girls from sixth (mean age: 11.5), eighth (mean age: 13.5) and tenth (mean age: 15.5) grade junior high school and from first grade senior high school (mean age: 16.5). In the participating schools the student response rate was 85% at age 11, 86% at age 13, 85% at age 15 and 81% at age 16. Non-responses comprised primarily either class- or school-level non-participation or student absence on the day the survey was administered.

Participation was based on parental passive consent. The students answered the internationally developed, self-administered HBSC questionnaire in the classroom after receiving standardized instruction from their teacher [39]. The data collection was anonymous. The students were asked not to report their names on the questionnaire and to return the completed questionnaire in a provided sealed envelope, to ensure that only the researchers had access to this information. The Privacy Ombudsman at the Norwegian Social Science Services assured that the study complied with privacy and confidentiality requirements. The study was sent to the Norwegian Western Regional Ethical Committee and was evaluated to not need ethical clearance.

Our findings indicate that cultural capital was a stronger predictor than material capital of disparities in consumption of fruit and vegetables and in the regular eating of breakfast and dinner, and it was the only significant predictor of consumption of sweets and sugared soft drinks among young people in Norway. The analyses support the argument that cultural capital and material capital are distinct dimensions of SES that work through different mechanisms to make unique and separate contributions to health. These findings accord with other studies using number of books in the household and FAS [47‐50] as SES indicators in research on eating habits among adolescents. For example, in a regional sample of Norwegian adolescents, Iversen and Holsen [48] found that students with high SES reported consuming more fruit and vegetables and less soft drink than did their counterparts with low SES, and that the number of books in the household was more strongly associated with eating habits than was family affluence. Vereecken and colleagues found a more regular meal pattern among adolescents in groups with higher family affluence [50].

Bourdieu’s concepts of cultural capital and habitus link structural and behavioural determinants of health by explaining how people’s behavioural options and preferences are related to lifestyle [30]. This approach encompasses both the conscious choice of health promoting behavior and the often milieu specific more or less routine patterns of perceptions, and suggests that adolescent’s food habits are influenced by parental perception and attitudes to food habits. Acquisition of cultural resources depends on the social class-specific learning context [51], and the family milieu represents a particularly important arena for learning eating habits during childhood and adolescence. Values attached to health, and knowledge about health effects of certain food choices, are class-specific cultural resources that structure people’s references and choices [30]. It is likely that students living in families with high cultural capital learn how to eat healthy at home. This perspective is supported by Farakas and Hibel [52], who analyzed several aspects of the home environment and concluded that home library size had a strong predictive validity as an indicator of parents’ attraction to the teaching role vis á vis their children. Parental social support is indeed shown to be more strongly associated with adolescent food habits than is social support from friends and social groups [53, 54]. Also habitual processes are at work here, and the family’s habits and norms for what kind of eating patterns are considered appropriate and required, are developed through this socio-cultural context. Adolescents living in a family context of regular meals and where diets high in fruit and vegetables and low in sugar and fat are desirable as well as accessible and available, are likely to develop healthy eating habits consistent with the collective lifestyle of the family.

Further economic circumstances influence a family’s opportunity to buy healthy food. The lower frequency of fruit and vegetable consumption among adolescents from families with low SES may reflect the high cost of fruit and vegetables in Norway. Focus groups, surveys and interviews have repeatedly shown that the relatively high cost of fruit and vegetables is a barrier to healthy eating for people with low incomes [55‐59]. Material capital is a resource that enables families to buy healthy food. High-cost food such as fruit and vegetables might therefore be less accessible for adolescents in families with low SES. However, economical capital approaches often fall short in elucidating the social differences observed in those health behaviours that cannot be explained by financial determination: unhealthy patterns of consumption that in large parts are determined by people’s norms and values [30]. When people are operating within a given economic frame of options, they also seem to bring cultural resources into play. Dibsdall and colleagues [60] showed that a barrier to increased consumption of fruit and vegetables in groups with low SES is not only the higher cost but also the group members’ preference for less healthy food items. Brug and colleagues [61] showed that a positive preference for fruit and vegetables increases the likelihood of their daily consumption. They also showed that taste preferences mediate differences in fruit and vegetable consumption between genders. Øygard [62] argued that food preferences differ between social groups, and that expensive food has a symbolic value that can be used to represent higher cultural capital, a perspective supported by Abel [16]. These points may explain our finding that the FAS, representing material capital, is an important predictor of consumption of fruit and vegetables but not of sweets and soft drinks, while number of books, representing cultural capital, is the strongest predictor of food preferences and meal frequency. Norms, values, health consciousness and habits attached to cultural capital therefore seem more important than economic factors with respect to healthy food choices.