Acculturation does not necessarily lead to increased physical activity during leisure time: a cross-sectional study among Turkish young people in the Netherlands

Physical activity during leisure time was assessed using one component of the Short QUestionnaire to ASsess Health enhancing physical activity (SQUASH) which includes questions about sports and other leisure time activities like walking, cycling, gardening and doing odd jobs during leisure time [42]. This instrument is comparable with the International Physical Activity Questionnaire (IPAQ) [43]. Dancing was added to the questionnaire since it is a common activity among Turkish girls and women. Total minutes of activity were calculated by multiplying frequency (days/week) by duration (min/day). Activity scores for separate questions were calculated by multiplying total minutes of activity by the intensity score. All activities were coded according to the Compendium of Physical Activities of Ainsworth [44]. The intensity score was expressed in MET's (i.e. metabolic equivalent or number of times resting metabolic rate). Subjects were classified as being active during leisure time when they undertook at least 30 minutes (or 60 minutes for people under the age of 18) of moderate activity per session at least one day a week. The main reason for this definition is the fact that more than half of the participants were not participating in any leisure time physical activity. Therefore, we considered the distinction between any activity versus none relevant for this population.

For people aged younger than 18 years, the cut-off point for moderate activity was 5 MET or higher and 4 MET or higher for people aged 18 and older [45].

The indicators of acculturation were based on Berry's approach whereby acculturation is considered in terms of orientation towards the majority culture versus culture of origin and social contacts with the host population versus contacts with people from culture of origin [46]. This resulted in the following two components:

'Cultural orientation' was measured by 10 items about language use with family members and friends, use of media, difficulties with reading the Dutch language, shopping preferences and emancipation as an example of Western norms and values [47, 48]. The cultural orientation scale was constructed using principal component and reliability analysis (alpha = 0.64).

The scores on the items in each scale were summed and a mean substitution was made for cases where one item was missing. To distinguish between the lower and the higher acculturated persons, the upper third was categorized as being high acculturated and the remaining two third as being low acculturated. Using this categorization we had large enough numbers of participants to perform stratified analyses.

Physical environment of the neighbourhood was assessed by a 19-item list containing neighbourhood characteristics on which participants could agree or disagree on a 4-point scale [49]. The variables included availability of sidewalks, availability of cycle lanes, neighbourhood aesthetics, perceived safety from crime and perceived safety from traffic. People who scored negatively on 8 or more items were categorized as living in a less attractive environment.

Occupational physical activity was measured by one question about how many hours a week people were engaging in physical activity at work such as walking a lot or carrying heavy loads. Participants were categorized as being active at work when they participated for at least 30 minutes a day (5 days a week) in occupational activities with moderate intensity (≥4.0 MET) [44].

Logistic regression analysis (SPSS 12.0.1 for windows) was used to assess the association between both indicators of acculturation and leisure time physical activity. All analyses were adjusted for age, sex, education and marital status. To assess whether these associations differed by the presence of contextual barriers (having children, occupational physical activity, less attractive neighbourhood), we conducted stratified analyses [50].

Of the total study population 44% was born in Turkey (first generation) and 56% in the Netherlands with at least one parent born in Turkey (second generation). Regarding the contextual barriers, approximately one-third of the participants perceived their neighbourhood environment as less attractive or had children under the age of 16. The barrier of occupational physical activity was found among only 16% of the participants (Table 1). Approximately 45% of all participants did not participate in any physical activity during their leisure time.

Table 1 also shows the characteristics according to the participants' level of activity. As expected, the participants with a greater orientation towards the Dutch culture or having more contacts with ethnic Dutch were more often physically active during leisure time than the participants who were less oriented towards the Dutch culture. Participants living in an attractive neighbourhood and the participants without children were more often physically active during leisure time than the participants who did have these barriers. For the overall measure of contextual barriers we also found that the participants with one or more of the mentioned barriers were less often physically active during leisure time than the participants with none of these barriers. For occupational physical activity we found no significant associations.

Table 2 shows the associations between acculturation and physical activity during leisure time expressed in Odds Ratio's (OR) with 95% Confidence Intervals (CI). These associations are adjusted for age, sex, education and marital status. Both indicators of acculturation were positively associated with physical activity during leisure time. The odds for 'cultural orientation' was 1.85 (CI: 1.19–2.85) and 1.77 (CI: 1.15–2.71) for social contacts (Table 2).

Table 3 shows the adjusted associations of the acculturation indicators with physical activity during leisure time stratified by 1) having children, 2) occupational physical activity and 3) attractiveness of the neighbourhood. Both indicators of acculturation had a significant influence on physical activity during leisure time among the participants without children, without occupational physical activity and among participants who perceived their neighbourhood as attractive. The odds of 'Cultural orientation' were 2.17 (CI:1.22–3.85) for participants who perceived their neighbourhood as attractive, 2.18 (CI: 1.29–3.71) for the participants without children and 1.76 (CI: 1.04–2.96) for participants without physical activity at work. For 'social contacts with ethnic Dutch' we found similar associations with odds of 1.76 (CI: 1.04–2.99) for the participants who perceived their neighbourhood as attractive, 1.87 (CI: 1.11–3.14) for participants without children and 1.83 (CI: 1.08–3.10) for the participants without occupational physical activity (Table 3). In contrast, among the participants who did experience the mentioned barriers, we found no significant associations between acculturation and physical activity during leisure time. However, in some cases the odds were on a similar or even higher level than within the group without the barrier, though not significant. This was found amongst others for the effect of cultural orientation within the group with occupational physical activity.

In figures 2 and 3, the associations between acculturation and physical activity during leisure time are shown for the participants in an "exercise-inhibiting context" (having at least one of the barriers) versus participants in an "exercise supportive context" (persons without any of the three barriers). This measure was calculated based on the sum score of all three barriers. Cultural orientation was significantly associated with physical activity during leisure time among the participants who did not experience any of the barriers (exercise supportive context: OR 3.24, CI: 1.51–6.96). This association was not found in the group who did experience at least one of the mentioned barriers (exercise inhibiting context: OR 1.40 (CI: 0.79–2.50). A similar, somewhat less strong, result was found for 'social contacts with ethnic Dutch' with Odds of 2.22 (CI: 1.11–4.41) within the exercise supportive context and 1.77 (CI: 0.99–3.18) within the exercise-inhibiting context.

Before drawing conclusions, some limitations must be mentioned. Firstly, as in many other studies we used cross-sectional data, which implies that no causal relationship between the acculturation indicators and the outcome measure could be demonstrated. For example, the influence of social contacts with ethnic Dutch people on physical activity during leisure time could perhaps be explained by the fact that people who participate in sport have more contacts with ethnic Dutch people. In the current study however, leisure time activities also included activities that were not organized, such as cycling, walking, running in the park or doing exercises at home, which do not necessarily involve more opportunities for contact with ethnic Dutch people. In addition, the main purpose of this study was to investigate the role of the contextual factors in the association between physical activity and acculturation, therefore the cross-sectional study design will not affect our main conclusions.

Secondly, the questionnaire for assessing physical activity during leisure time, was only validated for ethnic Dutch people [42]. To minimize the chance of misinterpretation or difficulties with understanding the questions we tested the questionnaire in a pilot study among young Turkish people and we adjusted the questionnaire to include dancing as a leisure time activity as this is a popular activity among Turkish women in particular. In addition, we used trained Turkish bilingual interviewers to help in cases of difficulties answering the questions.

The finding that more acculturated migrants were more physically active during their leisure time, is in line with results from other acculturation-studies among several ethnic minority populations, such as the Latino-, and Asian Americans in the US [17, 18, 20, 51, 52]. This positive association is often explained by the greater exposure to health promotion campaigns by people who speak the native language and who have many contacts with the host population. As a results their attitudes and norms towards physical activity become more similar to those in the host population. These people might also be better informed about the opportunities for physical activities, for example, how and where they can obtain access to sport facilities.

In addition to these studies, the results of the present study indicate that under certain conditions this positive effect of acculturation is not present. We illustrated that barriers such as having children (e.g. time barrier), living in al less attractive environment and participation in occupational physical activity modify the association between acculturation and physical activity during leisure time. Although several social cognitive theories that aim to explain behavioural practices, incorporated 'perceived barriers' in their model, this is often indirectly [53, 54]. According to these theories, behaviour will only be performed when a person perceives no barriers that could inhibit his/her behaviour. However, none of the acculturation studies we found paid attention to the role of barriers in the association between acculturation and physical activity. This is in line with the conclusion of Hunt et al. (2004) and Salant et al. (2003), who found, in their review-study, that acculturation-studies in general, do not include contextual factors [55, 56]. We suggest further study is necessary to unravel more of the potential contextual barriers that moderate the effect of acculturation on physical activity.

In contrast to most other studies we used a broader measure of acculturation than language use or language proficiency alone, instead we included items on shopping preferences, media use, and emancipation as well, in an attempt to cover a more general 'cultural orientation'. The use of 'language proficiency' or 'language use' as indicators of acculturation has been criticized by others as it would not necessarily reflect the migrants' adherence to the values and norms within the majority culture [57]. However, the majority of studies on acculturation use these indicators as they seem to be strongly related to several health related outcomes [58]. Nevertheless, we suggest that measuring different domains in which people acculturate might be a better reflection of the process of acculturation, than measuring only language use or language proficiency.

We assume that the pattern of varying influence of acculturation depending on the presence of contextual barriers, might also apply to other migrant populations. The positive association of acculturation with physical activity (during leisure time) has already been observed among different ethnic minorities and the barriers we included are acknowledged as important constraints for being physically active [17, 18, 20, 33, 34, 51, 52]. We further expect that our results could be generalized to older populations than those included in our study, as the barriers that we studied are in general more prevalent among adults. The majority of the older migrant adults, belong to the first generation and have on average a greater number of children and a lower socioeconomic position (e.g. more job related physical activity and living in less attractive neighbourhoods) than the young population that we studied [59].

Our findings provide indications to suggest that the level of physical activity during leisure time in non-Western migrant populations will not necessarily increase as a consequence of greater 'integration' in the host society among people with children, who participate in occupational physical activity or who are living in a less attractive neighbourhood. Therefore, we suggest that interventions aimed at specific ethnic groups with high prevalence rates of physical inactivity remain necessary. More specifically, our findings might imply that interventions aimed at promoting physical activity among migrants, should not only focus on the least integrated. Instead, effectiveness will probably be enhanced when interventions are sensitive to the social and environmental barriers, especially among low-income migrant populations.