1. Introduction
In general, young people in the WHO European Region enjoy better health and development than ever before but they are still failing to achieve their full health potential [
1]. Health experience during the critical period of adolescence has short- and long-term implications for individuals and society [
1]. Many health and risk behaviours are adopted and established during adolescence years [
2]. Often, healthy habits/behaviours continue into adulthood and affect the health status and mortality of the population [
1]. Studies so far have confirmed that the prevalence of poor subjective health outcomes increases with age and afflicts girls more than boys, with the gender gap increasing with age [
3]. There is substantial cross-national variation in the prevalence of subjective health outcomes, especially for self-rated health and multiple health complaints [
3].
Adolescents have many common health problems regardless of their origin and residence country, but prevalence differs by country/region, age and gender [
3]. In the regional comparisons, Estonia, Latvia and Lithuania are considered as a single Baltic region, but in particular, we still lack scientific knowledge in which indicators countries show similar trends and which they differ. So, even if Baltic countries have highly similar historical and social backgrounds [
4], it is still important to evaluate the health behaviour of adolescents in the Baltic region as compared to other Health Behaviour in School-aged Children (HBSC) study countries. We lack an international report that clearly shows adolescents’ health dynamics among Baltic countries. Specifically, the health of Lithuanian adolescents compared to other EU countries [
5], and physical activity in the Baltic youth [
6] were thoroughly analysed over a decade ago. At the root of Baltic adolescent’s health, there is a visible shortage of reports depicting the behaviour. Consequently, this article fosters us to minimise this gap within the literature and to better understand the dynamics of the indicators in Baltic countries.
At the most general level, daily physical activity is essential for optimal physical growth and development of the child [
7]. The literature shows that engaging in physical activity and spending less time in screen-based sedentary behaviours are related to fewer health complaints [
8,
9]. Physical activity has numerous positive effects on child and adolescent health, with good evidence for beneficial effects on adiposity in normal-weight and overweight children and adolescents [
10]. Despite the vast amount of knowledge available that states that adolescents partaking in regular physical activity are more likely to adopt a healthy and balanced diet that helps to improve physical and personal well-being [
11], adolescents’ physical activity has gradually decreased.
Similarly to physical activity, daily consumption of vegetables and soft drinks has been used as an indicator of a healthy lifestyle. Vegetable consumption among adolescents is linked to many positive health outcomes. Fruit and vegetable consumption is commonly considered as an indicator for overall diet quality, also previously described as weak modifiable behavioural determinants of overweight [
12]. Previously it was demonstrated that lower family affluence tends to be associated with higher soft-drink consumption, however the reversed pattern is applicable for Eastern European countries and Baltic countries. Consumption in aforementioned countries additionally may be considered as an indicator of wealth. The lowest levels of fruit and vegetable consumption are found in Northern Europe and the Baltic countries [
1].
Consumption of fatty foods and a high sugar diet, combined with low physical activity, are the main causative factors of childhood obesity. To prevent and decrease obesity, dietary changes and the introduction of physical activity are the most promising methods [
13]. The body mass index (BMI) is the most common index of adiposity status among children and adolescents. The previous HBSC studies have shown that, in general, overweight and obesity decrease with increasing age and boys tend to have significantly higher prevalence in almost all countries and regions at all ages [
1,
3]. The 2013/2014 HBSC study, for instance, indicated that increased prevalence of overweight adolescents was associated with low family affluence for boys in around half of the countries/regions and about two thirds for girls [
3]. High rates of overweight/obesity and a poor level of daily moderate-to-vigorous physical activity among children from low affluence families provide disturbing evidence highlighting the necessity of public health efforts to implement obesity reduction interventions for this disadvantaged population [
14].
It is important to better understand the factors associated with health and well-being, and their interrelation with family affluence for better strategy development, with the purpose of increasing the health of adolescents [
15]. The family affluence scale (FAS) is a valid measure for adolescent wealth, and a proxy of socioeconomic status [
15], which has evolved to be one of the most common tools or standard measurements used to assess the objective socioeconomic status of adolescents within the HBSC study [
16]. In this analysis, we address the health of adolescents in relation to the FAS, physical activity, vegetables and soft drinks intake and overweight prevalence.
Low relative affluence and poor subjective health emerges as a consistent significant association. Family wealth may have an indirect effect on health; however, other proximal determinants should be investigated [
3]. Therefore, it is important to keep track of trends and changes that are specific to more prevalent health behaviour variables. In this paper we explain the changes in adolescents’ health behaviour in addition to the similarities and differences among Baltic countries, and more generally, compared to the HBSC average results. Consequently, our study aimed to assess trends in adolescents’ physical activity, eating behaviours and BMI, and their differences in Baltic countries from 2006 to 2018.
3. Results
The study was based on data from the 2006–2018 HBSC international survey and the data were extracted to give information about Estonia, Latvia and Lithuania. We examined trends in adolescent health behaviours in four domains—moderate-to-vigorous physical activity, vegetable and soft drinks intake and BMI in relation to age, gender and FAS.
Prevalence of the health-related variables by country, year and gender are presented in
Table 2. Daily moderate-to-vigorous physical activity of Estonian (17.3% were active at least 60 min each day) and Lithuanian (20.4%) boys is significantly lower than the HBSC total (23.2%), as among Latvian boys the proportion is about the same level (22.2%). Among girls, only Estonian schoolchildren are significantly below HBSC average.
Consumption of vegetables is significantly lower in all Baltic countries as compared to the HBSC total, both among boys and girls (
Table 2). Consumption of soft drinks, on the positive side, was found to be significantly lower in Baltics, except Lithuanian boys, whose soft drinks intake in 2018 is about the same level as the HBSC total.
The prevalence of overweight or obese adolescents in the Baltic countries has moved closer to the HBSC average in each survey year. Since 2018, the prevalence of overweight or obesity in Estonian boys and girls and Latvian girls has been higher than among the HBSC countries in total.
When comparing the study years, as well as the effect of FAS and age, we can see that the trend of moderate-to-vigorous physical activity among Baltic adolescents is negative between 2006 and 2018 (
Table 3). The family affluence gradient is relevant for the physical activity of adolescents in the results of boys and girls in all Baltic countries. It is also apparent from the results that physical activity reduces significantly by age groups, both for boys and girls.
The daily consumption of vegetables has increased since 2006 (
Table 4). The biggest changes have occurred among adolescents in Estonia, both for boys (OR = 1.74 (1.51–2.00)) and girls (OR = 1.88 (1.65–2.14)). After adjusting the results for age and FAS, there are significant changes among Estonian, Latvian and Lithuanian boys and Estonian and Lithuanian girls, but not among Latvian girls.
Unfortunately, the consumption of vegetables decreases by age among adolescents in Baltic countries (
Table 4). FAS is positively related with vegetable consumption among boys and girls in all three Baltic countries. The highest FAS effect on the consumption of vegetables is in Estonia (OR = 1.11 in boys and 1.12 in girls).
Soft drinks consumption has generally decreased when compared to 2006 (
Table 5). Only Lithuanian boys have remained at the same level of soft drinks consumption. When adjusting the results for age group and FAS, soft drinks consumption has declined significantly among Baltic adolescents in all three countries except for Lithuanian boys. The biggest decrease is among Latvian girls (OR = 0.30 (0.24–0.39)).
FAS is positively related to soft drinks consumption in boys in Estonia (OR = 1.10 (1.06–1.15)) and Latvia (OR = 1.07 (1.04–1.11)), while in other groups better family affluence does not affect adolescents’ soft drinks consumption (
Table 5). In age comparison, soft drinks consumption in 11-, 13- and 15-year olds are similar. Only Latvian 13-year-old boys consume soft drinks 1.24 times more than 11-year olds. Estonian 15-year-old girls consume about half as many soft drinks as 11-year olds.
Overweight or obesity is almost two times higher among boys and three times higher among girls when compared to 2006 (
Table 6). The smallest change in weight is in Estonian boys. Considering the impact of FAS on BMI, higher family affluence significantly reduces obesity in Estonian boys and girls and Lithuanian girls, but not in Latvian adolescents and Lithuanian boys.
5. Conclusions
As well as the cultural and historical–political background in the Baltic States being similar, the patterns of health behaviours of adolescents in Estonia, Latvia and Lithuania since 2006 are also quite similar. In general, it can be noted that while in 2006 the prevalence of overweight adolescents in the Baltic states was about one third lower than the HBSC average, by 2018 this indicator was even higher than the HBSC average. In 2018 the level obesity and overweight is almost twice as high in boys and three times as high among girls, when compared to 2006. The effect of FAS on BMI has not been unequivocally proven, as higher family wealth significantly reduces obesity among Estonian adolescents and Lithuanian girls, but not among Latvian adolescents. Consumption of soft drinks also follows the average trend of HBSC, as consumption is declining among both boys and girls in 2006–2018. Although the consumption of vegetables in the Baltic countries has increased in each year of the study, it is still below the HBSC average. In all Baltic countries the trend of moderate-to-vigorous physical activity among adolescents is negative between 2006 and 2018, but the results are relevantly influenced by the family affluence gradient. In terms of physical activity, Estonian adolescents should follow the example of their neighbours; in 2006–2018, more adolescents in Latvia and Lithuania have been physically active for at least 60 min every day than in Estonia.
Although the changes in Baltic adolescents’ health behaviours between 2006 and 2018 are quite similar, the study also enables us to highlight the differences between the three countries and address the most problematic topics for each country. When compared to their neighbours, Estonian adolescents’ lower physical activity together with higher overweight/obesity rates represent the topics that need more attention. Lithuania and Latvia, on the other hand, need to focus on improving adolescents’ dietary habits, specifically, on reducing soft drinks consumption in Lithuania and eating more vegetables in Latvia.
This study highlights the importance of exploring the long-term changes in health indicators, with a special focus on obesity, physical activity and nutritional habits. According to our findings, obesity rates in Baltic adolescents almost doubled, levels of physical activity diminished, while nutritional habits improved throughout the study years. Taking into account the lack of physical activity alongside the improvements in eating habits, obesity and overweight are still problems. This outcome further brings our attention to the energy balance between consumed and expended calories, which must be respected. Physical inactivity is especially concerning when viewed through a health lens as calories that are not expended are converted into fat, which further predisposes health problems connected with overweight and obesity.