Clustering and correlates of screen-time and eating behaviours among young children

Unhealthy eating behaviours and too much time spent being sedentary using screen-media are highly prevalent in today’s society [1, 2]. For example, in the United Kingdom (UK), children as young as 5 years of age are using screens (television (TV), computers and tablets) for more than 27 h a week [1]. Furthermore, less than 8% of primary school-aged children meet the UK recommendations for fruit and vegetable (FV) intake [2], yet more than 13% of 4–10 year olds’ food energy comes from extra sugars [2]. A recent report from the Children’s Food Trust suggested that 4–7 year-olds were the most likely age group to eat cakes and biscuits, sweets and chocolate at least once per day (often more) [3]. Health-related behaviours, such as screen-time (ST) and unhealthy dietary behaviours, are established in childhood and tend to track throughout adolescence and into adulthood [4, 5] and so it is important to try to promote the establishment of healthy behaviours from the early years.

A wealth of evidence exists regarding the adverse health consequences associated with eating unhealthy diets (too few FV; too many energy-dense foods (ED); for example [6‐8]) and spending too much time on screen-based sedentary activities (e.g. sitting to watch TV/DVDs, using computers, etc. [9, 10]). This evidence has tended to focus on these health risk behaviours independently but emerging evidence suggests that they might actually cluster and co-exist in young people [11, 12]. ST and unhealthy dietary behaviours have been found to cluster in 9–10-year-old [13] and 11–12-year-old [12] British children. Specifically, 11–12-year-old adolescents who consumed low levels of FV also consumed higher levels of ED snack foods and spent more time using screens [12]. Thus, it is plausible that health-promotion interventions, such as to prevent obesity and later ill-health, might be more effective by targeting a combination of behaviours, rather than just one.

The development of effective interventions requires an understanding of the most important correlates and determinants of the targeted behaviours. In young people, the home environment is key for health behaviours, with parents’ own behaviours and parenting strategies and practices having a significant influence on children’s health behaviours [14‐16]. For example, family TV time, rules for screen-time, and access to screens at home are significant correlates of children’s ST [14]. Furthermore, parental modelling of eating FV and ED snack foods are significant correlates of child consumption of these food items, as are factors such as home availability and accessibility of food items, restriction of foods, and eating in front of the television [15, 16]. While research has typically focused on correlates of individual health behaviours there has been a recent trend towards the study of correlates of clustered behaviours [11‐13, 17], however, much of this research has focussed on sociodemographic predictors [13, 17]. A recent study among 11–12 year old children examined a wider range of correlates and found numerous factors consistently associated with the co-occurence of high ST, high ED snack consumption and low FV consumption [12]. These included eating while watching TV, eating at the TV with parents, and the availability and accessibility of ED snack foods at home [12].

Given evidence that the odds of having multiple risk behaviours increase over the course of development [18], and that healthy habits are established early in life, there is value in exploring younger children, before health behaviours become too engrained. However, a recent review aiming to identify clustered patterns of diet, physical activity and sedentary behaviour among children or adolescents found only one study among children < 9 years of age [11]. In this one study, Cameron et al. [19] found that clusters of healthy (e.g. physically active and high FV) and unhealthy behaviours (low physical activity, high ST and low FV consumption, and consumption of ED food/drink) were concordant in mothers and their children (mean age 9.4 years), particularly those defined by sedentary behaviors and consumption of ED food and drink. Further evidence is required examining correlates of co-occurring behaviours and how health behaviours cluster in younger children.

Based on the identified gaps in the extant research literature, the purpose of this study was to examine the sociodemographic, behavioural, and home physical environmental correlates of co-occurring screen-time and unhealthy eating behaviours and to assess the clustering of screen-time and unhealthy dietary behaviours in young children. Pursuant to the distinctions used in epidemiological research between co-occurrence and clustering [20, 21], throughout this manuscript co-occurrence describes the concurrent, but independent, engagement in two or more health related behaviours (also referred to as patterns of health behaviours or prevalence of behaviour combinations). Clustering refers to an underlying association between co-occurring behaviours.

The aim of this study was to examine the sociodemographic, behavioural, and home physical environmental correlates of co-occurring screen-time and unhealthy eating behaviours and to assess the clustering of screen-time and unhealthy dietary behaviours in young children. Given the attention that ST is increasingly receiving in the media and literature on children’s health, it is important to extend our knowledge about how other behaviours may co-occur and cluster with ST and what correlates seem to be important for such clusters. This allows a more nuanced approach to ST research.

While just under half of the children studied had none or only one risk behaviour, it is noteworthy that just under 20% had all three risk behaviours. This can be considered a large proportion and highlights a clear target for intervention. The cluster of low fruit and vegetable consumption, high ED snack consumption, and excessive ST and the two-risk cluster of high ED snack consumption and excessive ST both occurred more frequently than expected. Children engaging in too much ST also engaged in unhealthy eating behaviours. Although these findings did not attain significance, they are important for shaping the development of future interventions as they indicate the clustering, or co-occurrence, of unhealthy behaviours and suggest that behaviour change interventions might benefit from targeting ST and dietary behaviours concurrently or simultaneously. Given that evidence for the effectiveness of existing interventions which solely target sedentary behaviour is unconvincing [33], new interventions are required and our findings would suggest that these should target ST and diet together in efforts to bring about improved health behaviours. However, this would need to be guided by the data on the correlates of such behavioural clustering.

Our study showed that families of low household income, parents with high TV viewing, and parents reporting high availability of ED snacks in the home were at higher odds of having children in the three risk behaviour group than the none or one risk group. The finding that children from low income households were at higher odds of having all three risk behaviours is corroborated by those of Hardy et al. [17] who found evidence of clustering of sedentary behaviour, physical activity and dietary behaviours in Australian adolescents, particularly among adolescents from low income households. Our findings show that such relationships start early in childhood in this UK based sample. It has been known for some time that socio-economic status (SES) is associated with higher levels of TV viewing [34] and also with poorer dietary intake [35]. However, how to address this issue has been shown to be more problematic. Low SES might be associated with more barriers to be outside of the home, such as greater crime in the local area or less open and green space, hence increasing the likelihood of greater indoor sedentary time. Cost is also a recognised barrier to parents purchasing healthy foods for their children [35, 36]. While these barriers are acknowledged, few interventions have specifically addressed the issue of SES in relation to poor diet and ST in the home, yet the current findings add further weight to this group being in need of support.

The finding that parents with higher TV viewing were at higher odds of were at higher odds of having children in the three risk behaviour group than the none or one risk group aligns with the findings of Cameron et al. [19], who showed that clusters of unhealthy behaviours were concordant in mothers and their children, particularly those defined by sedentary behaviours and consumption of ED food and drink. The associations between parental modelling of individual healthy (e.g. physical activity [37] and consumption of fruits and vegetables [15]) and unhealthy (e.g. high ST [14] and ED snack food consumption [38]) behaviours and child behaviours are well established in the literature, and our findings that parental modelling of TV viewing is associated with the co-occurrence of 3 unhealthy behaviors is novel and further develops this literature. Our findings suggest that parental TV viewing behaviour has the potential to transfer across to different health behaviours in children. Strategies to un-couple unhealthy behaviours need to address parental as well as child behaviours and should focus on the creation of a healthy eating and active home environment, screen-free eating occasions, parents modelling healthy behaviours (i.e. switching off screens when with children) and finding opportunities for whole family active alternates to sedentary screen-based activities.

Higher availability of ED snacks in the home increased the odds of having children who exhibited the co-occurrence of all three risk behaviours. This may be a surrogate measure for the availability of less healthy foods within the household. Moreover, children’s consumption of ED snacks in front of the TV was also associated with the Low FV/High ED and High ST/High ED pattern, suggesting that ED snacking is problematic in 5–6-year-olds and another important target for intervention. Not only might different food shopping strategies be needed, but healthy and palatable alternatives are also required (e.g., chopped ready prepared fruit). Parents, particularly those from low SES backgrounds, might benefit from advice regarding cost effective ways to purchase healthy foods (e.g., buying frozen or tinned foods as a way to reduce waste), as cost and waste are important predictors of parents not repeatedly offering healthy foods to their children [36].

It is also interesting that we found that children eating breakfast in front of the TV on three or more days a week were at higher odds of being in the High ST/Low FV group than the non or one risk behaviour group compared with those who ate breakfast at the TV on two or less days a week. Previous research has demonstrated an underlying association between TV viewing and lower intakes of fruit and vegetable consumption [39]. Eating meals such as breakfast in front of the TV has been linked to lower intakes of fruits and vegetables and higher intakes of unhealthy foods [40]. Distractions, like the TV, have been shown to increase food intake [41] and TV viewing might be a strategy employed by parents in an effort to facilitate breakfast intake during busy morning routines. Eating breakfast in front of the TV could reduce opportunities for eating as a family, which is important for an array of health behaviours [42]. Furthermore, evidence suggests that SES is inversely related to eating in front of the TV (e.g. [43]) and so this reflects another difference in children’s health behaviours among SES groups. Given the young age of the children in our study, eating breakfast away from screens represents another area to be targeted in future.

The findings of this research are valuable for helping to inform the development of future health-promotion interventions. This research has highlighted clusters and patterns of high-risk health behaviours in young children which warrant targeting in future programmes aiming to reduce childhood overweight/obesity and improve children’s activity levels and healthy eating behaviours. Strengths of this research include the assessment of multiple risk factors and analysis of co-occurrence of these behaviours and the use of a sample of parents of young children. Limitations include the fairly homogenous sample and low response rate, which limits generalisability, the moderate sample size, and the cross-sectional nature of the data. The accuracy of the parent-reported child food frequency may be impacted especially for parents whose children eat school lunches and may therefore not be aware/sure of what/how much their children are eating and could potentially have led to an under or over-reporting of food items. Furthermore, the adaptations made to the ASAQ to assess children’s screen-based behaviours may have impacted on the reliability and validity of the measure and could have led to inflated/deflated values for reported ST. Caution is required in interpreting our findings in light of these limitations.

In conclusion, parents’ own behaviour has been identified as an important influence on the co-occurrence of ST and unhealthy dietary behaviours in children as young as 5 years. Uniquely, our findings extend past research to highlight the co-occurrence and clustering of multiple health risk behaviours in young children. There is therefore a need for further research into the development of behavioural clustering in young children to identify and further understand the mechanisms underlying the synergy among health behaviours. Feasibility interventions that promote reductions in both ST and unhealthy dietary behaviours reciprocally, while simultaneously focusing on changing parental behaviours, are warranted.