1. Introduction
Physical fitness (PF) is a set of health- or skill-related attributes [1]. The elements of health-related PF embrace body composition, muscular endurance, muscular energy, cardiovascular endurance and suppleness, which are widely recognized as markers of health-related outcomes throughout life [2,3]. The adolescence period is a crucial time for PF improvement. Improving PF in adolescents is of nice significance not only to improving their tutorial performance, high quality of life, cognitive capability and psychological health but in addition to enhancing the standard of nationwide well being [4,5,6]. However, the decline of PF in adolescents has become a global public well being drawback. In latest years, although the PF of Chinese adolescents has typically improved, the trend of PF is still not optimistic. According to the results of the 8th National Survey on Student Physical Fitness and Health released by the Chinese Ministry of Education in 2021, solely 17.7% of students aged 13–22 might achieve a “good” or “excellent” score of PF [7]. Therefore, given the current state of affairs of PF amongst Chinese adolescents, it’s necessary to take effective measures to improve their PF.There are varied elements that have an effect on adolescents’ PF, similar to genetics, biological characteristics, dietary habits and bodily exercise (PA) [8,9,10]. Studies have proven that PA and food plan are associated with PF in adolescents. Relevant research can be divided into the next three classes. (1) Association of PA and food regimen with weight standing: The results of several studies have indicated that intermittent fasting is useful for physique weight, however diet-induced weight adjustments are generally short-lived and higher benefits may be gained through vigorous PA [11,12]. Bogataj et al. have demonstrated that just 8 weeks of school-based high-intensity interval training with three classes per week and nutrition intervention can enhance upper body muscle and physical cardio performance in adolescents and help scale back BMI in chubby ladies [13]. Oh et al. identified dietary patterns in Korean kids and adolescents, and found that the “fast meals and soda pattern” was positively associated with waist circumference, serum insulin and BMI, while the “white rice and kimchi pattern” and “oil and seasoned vegetables pattern” indicated a preventive effect on these parameters [14]. (2) Effect of food plan and PA on health: Previous research have found an effect of diet on cardiorespiratory health (CRF) and metabolic syndrome (MetS) [15,16]. For instance, CRF was positively associated with frequent consumption of fruits, greens, bread and dairy products [15,17]. Shahinfar et al. showed that adherence to the mixed dietary pattern was associated with increasing odds of MetS in Iranian adults [18]. Moreover, Wenjie et al. discovered that sufficient calcium consumption and the improved CRF have been important for the development of excellent mental well being in adolescents aged 12–13 years [19]. (3) Relationship between Mediterranean diet and PA and different parameters of PF: The Mediterranean food regimen (MD) is postulated as one of many healthiest dietary patterns that exists [20]. The authors concluded that optimum adherence to the MD pattern was related to higher CRF and PA ranges as nicely as high levels of muscular energy [21,22,23,24]. For an occasion, Cristina et al. discovered that higher adherence to the MD pattern was related with larger CRF and lower limbs muscular strength and velocity agility [25]. Pablo et al. additionally confirmed that larger levels of CRF in boys and girls were related to medium and high adherence to the MD [26]. However, some studies indicated the constructive correlation between the MD pattern and better CRF and speed agility solely in boys [27,28].Although several studies have analyzed the associations between dietary patterns and PA with PF among adolescents, there are still several problems. First, the present studies are controversial about the correlation between parents’ academic level and PF. One examine showed that the tutorial level of German mother and father was positively correlated with their children’s aerobic fitness [29]. However, a Swiss study found that parents’ academic level affected kids in another way, with the mother’s training degree showing to have a larger impact on children’s PF [30]. Another examine found that these Catalan children whose fathers had larger training had decrease waist circumference and BMI [31]. Second, the measurement requirements of Chinese and overseas students’ PF are completely different. For an instance, Spain measures higher body muscular strength of scholars using a hand dynamometer with adjustable grip, whereas China doesn’t measure girls’ upper physique muscle energy and solely makes use of pull-ups to measure the upper body muscular strength of boys [24,32]. Third, most studies on the relationship between dietary patterns and PF have focused on the MD sample. The MD sample is characterized by excessive consumption of vegetables and fruits, nuts, cereals, fish and olive oil and minimal amounts of purple meat and dairy products, which is type of completely different from the grain-based Chinese dietary pattern [25]. Currently, we have not discovered any stories on the interaction between dietary patterns and PF in Chinese adolescents. Therefore, it is necessary to discover the connection between dietary patterns, PA and PF amongst Chinese adolescents based mostly on Chinese physical health measurement requirements and dietary culture.This examine was designed with the next basic aims: (1) to comprehensively evaluate the physical health status of adolescents (11–18 years old) in Shandong Province; (2) to explore the relationship between food plan, physical activity and bodily health; and (3) to further analyze the differences between girls and boys within the relationships between dietary patterns, physical activity and totally different parameters of PF. We hope that the findings of this research can provide a valid and specific theoretical basis for bettering the physical health of Chinese adolescents.
2. Materials and Methods
2.1. Participants and Study Design
This is a cross-sectional research that is a part of a special program to research the established order of health and health-related behaviors of Chinese junior and senior highschool college students. Detailed sampling strategies have been revealed elsewhere [33]. Briefly, the pattern for this research was selected utilizing a probability-proportional-to-size sampling methodology through the 2020–2021 semester. Ultimately, eleven,063 adolescents aged 11–18 years had been recruited for the study. After excluding illogical samples and those missing data on PF or diet, a total of 8796 individuals were finally included for evaluation. Teachers, mother and father and students crammed out a consent form prior to enrollment on this survey. The research was approved by the Ethics Committee of Shandong University, China ( ). 2.2. Data Availability
The data used on this research are publicly out there in the Population Health Data Archive [34]. 2.three. Measurements
2.3.1. Demographic Factors
They included gender, age, place of residence (rural/urban), parents’ academic degree (junior high school and under, highschool, college and above), and household economic standing (poor, middle, good). This info was collected by way of a self-reported questionnaire for participants.
2.three.2. Physical Activity Measure
PA was evaluated by the Physical Activity Questionnaire for Adolescents (PAQ-A). This scale is a revised version of the Physical Activity Questionnaire for Children (PAQ-C), which is designed to assess the PA level of adolescents [35]. It is on a 5-point scale (1–5), with larger scores indicating higher levels of PA. The outcomes can be divided into two categories: low PA ranges (1–1.9 points) and high PA levels (2–5 points) [36]. The validity and reliability of the PAQ-A has been validated among Chinese adolescents [37]. This study also demonstrated that the questionnaire has good internal consistency and structural validity: the Cronbach’s alpha worth was 0.eighty two; the Kaiser—Meyer—Olkin (KMO) value was zero.83; and for Bartlett’s test, p 2.3.three. Dietary Assessment
Participants’ dietary status was assessed using the modified Chinese Diet Quality Questionnaire (DQQ), a 5-point scale (1–5) for fast qualitative and quantitative analysis of participants’ food regimen quality. The DQQ contains three food plan scores: GDR-Healthy score, GDR-Limit rating and total GDR score. The GDR-Healthy score reflects international recommendations for health-protective meals in healthy diets. The GDR-Limit score reflects global suggestions for limiting dietary components. Lower overall GDR score, lower GDR-Healthy score and higher GDR-Limit rating point out poorer food plan quality [38]. Studies have shown that the DQQ is usually a valid software for assessing the food plan high quality of Chinese children and adolescents aged 7–18 [39]. The DQQ contains 29 food teams. Considering the dietary habits of individuals in Shandong Province and the aim of this examine, we removed cereals and cheese from the DQQ. Additionally, the food items had been combined into 17 teams in this study to facilitate adolescents filling out the questionnaire. Each participant was required to answer the question (How typically have you ever eaten this type of meals prior to now week?), and the solutions were divided into five ranges (1 = “0 times”, 2 = “1–2 times”, 3 = “about as soon as every 2 days”, 4 = “about once a day”, or 5 = “more than once a day”). In this examine, the Cronbach’s alpha was zero.87, and the questionnaire was demonstrated to have good construct validity (KMO 0.ninety one, Bartlett’s test p 2.3.4. Physical Fitness
Trained bodily education lecturers administered all PF exams in accordance with standard working procedures The coaching was conducted by way of workshops and the particular procedures for knowledge collection have been described in a previous paper [33]. PF was assessed by the Chinese National Student Physical Fitness Standard (CNSPFS) battery revealed by the Ministry of Education of the People’s Republic of China, which is a reliable and legitimate instrument for assessing PF in adolescents [40]. The total score of the participants’ PF take a look at is one hundred points, and the proportion of the score for every item and the take a look at methodology are shown in Table 1. 2.4. Statistical Analysis
All knowledge have been analyzed by IBM SPSS Statistics Version 26.zero (IBM Corporation, Armonk, NY, USA). Continuous variables were expressed as imply (M) and commonplace deviation (SD), and numbers (N) and percentages (%) had been reported for categorical variables. Independent samples 2-tailed t-test, one-way analysis of variance (ANOVA) take a look at or Chi-square take a look at have been used to compare the variations between teams of categorical variables, as acceptable. Furthermore, we carried out multiple comparisons utilizing Bonferroni-corrected p-values to account for inflation of type-I errors because of a number of comparisons made. To examine the connection between predictors (diet and PA) and outcomes (PF), we first analyzed their relationship utilizing linear regression. Then, factor analysis was used to research the dietary patterns of the individuals. As an exploratory analysis, we further investigated the differences in the relationship between PF and dietary patterns in boys and girls. Specifically, every PF was regressed on the dietary patterns after adjusting for basic confounders corresponding to age, place of residence, parents’ academic stage and household economic standing (Model 1). Other analyses adjusted for high PA ranges (Model 2). Odds ratios and their 95% confidence intervals obtained from the mannequin were reported. A p-value
3. Results
three.1. Sociodemographic Characteristics of the Participants
In total, 8796 college students (4332 (49.2%) boys; 4464 (50.8%) girls) had been included within the final statistical evaluation of this examine. The demographic characteristics of the participants are summarized in Table 2. The imply age of the individuals was 14.32 years and imply PF score was seventy five.sixty seven. The results showed vital variations in PA, food plan, and PF between boys and girls. A significantly higher share of boys than women have been energetic in PA (58.1% vs. forty six.5%). However, the proportion of boys with a BMI above regular was considerably larger than that of girls (27.4% vs. 21.3%). Girls had a considerably higher imply general GDR score (7.53 vs. 7.45) and imply PF rating than boys (77.34 vs. seventy three.94).The mean PF scores of adolescents varied extensively amongst cities in Shandong province, ranging from 70.58 in Liaocheng to eighty one.2 in Linyi (Figure 1). In phrases of boys’ PF, boys in Heze had the highest mean PF rating of eighty.fifty four, whereas boys in Dongying had the lowest imply PF score of sixty eight.32. Girls in Linyi had the very best imply PF score of eighty three. three.2. Physical Fitness Status of Adolescents in Shandong Province
Table three shows the means and deviations of the PF checks by age and gender, and the variation of boys’ and girls’ efficiency on the various PF exams with age is proven in Figure 2. It can be observed that ladies had greater PF scores than boys in all age groups. In particular, girls carried out significantly higher than boys on the CRF check. Boys performed better than girls on the motor take a look at. However, boys had poorer higher physique muscular power and only the 17-year-old boys passed the pull-ups take a look at with an average rating (70.07). three.three. Relationship between Physical Fitness and Other Variables
In this examine, the PF score was used because the dependent variable, and the relationship between PF and numerous components was analyzed by a quantity of linear regression (Table 4). The results showed that girls’ PF performance was 26.38 occasions (OR 26.38, 95% CI sixteen.97–41.01) greater than that of boys. Adolescents dwelling in rural areas had considerably greater PF scores than those dwelling in city areas, and this phenomenon was extra pronounced amongst boys (OR eight.00, 95% CI 3.89–16.45). Furthermore, we discovered that participants’ PF scores became higher as individuals aged. The PF scores of boys whose fathers had a college or above level of training have been 4.36 times (OR four.36, 95% CI 1.32–14.36) higher than these whose fathers had a junior high school or below level of training. Compared to boys whose moms had a junior high school or under degree of education, boys whose moms had a college or above degree of education had 78% decrease (OR zero.22, 95% CI zero.063–0.76) PF scores. A statistically important positive correlation was discovered between PF scores and PA levels (p 3.four. Dietary Patterns of Adolescents Aged 11–18
The examine performed issue analysis (based on principal part analysis) to research participants’ dietary patterns (DPs) based on the percentage energy consumption of 17 meals groups. To determine the number of DPs, we thought of eigenvalues greater than zero.four and scree plots. Finally, 4 mutually unique DPs were recognized, as shown in Figure three. The DP was named in accordance with salient food traits. DP1 was named the “unhealthy meals pattern”, and was characterized by excessive issue loading from sugar-sweetened beverages, packaged ultra-processed salty snacks, deep-fried meals, Western fast-food, immediate noodles and processed meats. Similarly, the other three DPs have been named DP2—tuber and legume pattern (white root/tubers, potato, legumes, purple and orange vegetables), DP3—protein and seafood sample (eggs, milk, unprocessed red meat, fish and seafood), DP4—vegetable and fruit pattern (green leafy vegetables, other greens and fruit). These 4 DPs could clarify 22.67%, 15.29%, 13.89% and 12.47% of the variance, respectively. Food variables with higher issue loadings in the DP indicated higher intake. Each participant had 4 DP scores, with the most important DP rating indicating their desire for that DP. As shown in Figure 4 and Figure 5, 50.6% of the members tended to be DP4, and fifty five.90% of them were girls; 15.8% of individuals most well-liked DP1, of which fifty four.1% were boys. three.5. Associations between Dietary Patterns and Physical Fitness
Table 5 showed the outcomes of the linear regression evaluation of the predictor (DPs) for different parameters of PF after adjusting for the essential confounders (age, place of residence, parents’ academic level and family financial standing; mannequin 1) and additional adjustment for PA confounders (model 2). DP1 was negatively correlated with CRF in boys (OR 0.fifty six, 95% CI zero.31–0.98, p p p p p p p four. Discussion
The purpose of this study was to look at the associations between PA ranges, DP and PF among Chinese adolescents, considering demographic components similar to gender, age, place of residence, parents’ academic degree and household financial status. We had several important findings.
4.1. Physical Fitness
The common PF score of the individuals was 75.sixty seven, and 39.4% of participants could obtain a “good” or “excellent” ranking from PF. Compared with 2016, the PF performance of adolescents in Shandong Province has been tremendously improved. Specifically, their muscular endurance and muscular power improved. For example, the one thousand m/800 m run was shortened by 8.1 s and 5.5 s for girls and boys, respectively, and the standing long bounce was improved by 7.fifty one cm and three.00 cm, respectively. Additionally, the common number of pull-ups for boys also increased by 1.18 [41]. However, fifty five.8% of the boys still failed the pull-ups test, and even 31% scored zero. The boy’s upper body muscular strength is worrying and it’s essential to hold out targeted workout routines for boy’s upper physique muscles. Secondly, we found statistical differences in PF by gender, place of residence and PA. We noticed that ladies had better PF efficiency than boys, particularly in CRF. Adolescents residing in rural areas had higher PF scores than those dwelling in city areas; active PA may significantly enhance adolescents’ PF performance, and PF efficiency improved with age. These findings are consistent with previous studies [42,43,44]. However, the PF scores of 18-year-old boys on this research were considerably lower than those of 17-year-old boys. This end result could also be because of the small sample measurement of 357 (4.1%) for 18-year-old boys. The specific causes for this shall be explored in detail sooner or later by further expanding the sample size.It is noteworthy that parents’ academic stage was only related to boys’ PF in this research. Boys whose fathers had a college or above degree of education carried out considerably higher in PF than those whose fathers had a junior high school or under degree of education. However, boys whose moms had a college or above stage of schooling performed worse in PF than those whose mothers had a junior highschool or under stage of education. These findings are inconsistent with the findings of earlier research [29,30]. These discrepancies may be partly attributable to the different division of parenthood in Chinese families. Chinese fathers play a key role in their children’s PA decisions and behaviors [45]. Adolescents whose fathers were highly educated engaged in considerably more PA per week than these whose fathers have been much less educated, and PA levels were positively associated with adolescents’ PF efficiency [46,47]. However, Chinese moms, especially those from better-off and higher educated households, make investments more in their children’s education and are extra keen to enroll their youngsters in cram schools, which significantly reduces their children’s PA time [48]. 4.2. Dietary Patterns
Four DPs had been identified in this examine, together with the unhealthy food pattern, tuber and legume pattern, protein and seafood sample and vegetable and fruit sample. It can be discovered that the DPs derived from this examine are significantly different from the Korean DP and MD patterns [14,25]. According to the suggestions of the “Dietary Guidelines for Chinese School-aged Children (2022)”, school-age children ought to drink milk daily and never drink sugary drinks. However, we discovered that 15.8% of the participants most well-liked the “unhealthy food pattern”, and only about half of them (58.8%) drank milk each day. It is obvious that the milk consumption among Chinese adolescents is comparatively low, and the promotion of scientific consumption concepts of dairy products must be strengthened to lift the right awareness of dairy merchandise among adolescents and their dad and mom.Additionally, 24.3% of individuals in this study had been chubby, which is larger than the findings in 2017 [49]. Studies have shown that the prevalence of overweight amongst Chinese adolescents continues to increase [50]. Furthermore, we found that GDR scores have been related to BMI in Chinese adolescents, with higher GDR-limit scores associated with larger odds of weight problems and higher total GDR scores related to lower odds of obesity [38]. However, the chubby individuals on this examine consumed extra unhealthy meals than those that have been obese. This could additionally be due to misperceptions about their weight among overweight people. Some research have reported that adolescents who perceive themselves to be heavier have more restrictions on their diets [51]. Therefore, so as to effectively curb the epidemic of chubby and weight problems amongst Chinese adolescents and to advertise their wholesome growth, it is essential to enhance the dissemination of dietary health information among Chinese adolescents, particularly boys, and guide them to develop the right view of well being. 4.3. Physical Activity, Dietary Patterns and Physical Fitness
Further analysis of various PF checks revealed that DPs had completely different results on the PF of girls and boys. Energy-dense and low-nutrient junk meals is a serious part of DP1. Excessive consumption of junk meals can lead to extreme accumulation of vitality, weight problems and different metabolic illnesses [43]. Another investigation reported that excessive consumption of junk meals in obese college children is associated with derangement of sympathetic cardiovascular features and decreased pulmonary features [52]. Our findings have confirmed that DP1 was negatively correlated with CRF in boys. This could also be due to the greater prevalence of obesity amongst boys on this sample. Whether there are gender differences in the impact of junk food on CRF among Chinese adolescents must be additional explored. DP2 (tuber and legume pattern) is rich in white root/tubers, potato, legumes, pink and orange greens and low in seafood. It is a major food source of isoflavones, phytosterols, lecithin, chlorophyll, lutein, lycopene, anthocyanins, polyunsaturated fatty acids and dietary fiber [53,54]. Previous research have shown that there was a adverse affiliation between DP2 and abdominal weight problems among adolescents [16]. However, in the current research, DP2 was solely negatively related to BMI in women but not considerably associated with BMI in boys. In addition, average consumption of high-quality protein has been shown to help enhance muscular strength and speed-agility in adolescents [55]. However, we discovered that DP3 (protein and seafood pattern) had completely different effects on PF in girls and boys. For girls, DP3 was positively related to motor health, whereas for boys, DP3 was positively correlated with higher body muscular strength. To look at the function of PA on the connection between DPs and PF, we additional adjusted the analysis for lively PA. The results confirmed that the relationship between DP1 and girls’ BMI grew to become important after adjustment for active PA. One rationalization is that bodily lively people make more healthy and more beneficial food choices to find a way to perform higher [56]. However, we didn’t find a vital change in the relationship between DP1 and boys’ BMI due to adjustment for energetic PA. In the lengthy run, more investigations are wanted to explore this cause. four.four. Study Limitations and Future Research
Some limitations on this study must be explained. First, this examine was based on participants’ self-reports, which may be subject to self-report bias. Second, although gender, age, place of residence, parents’ instructional degree and family economic standing had been accounted for in our analyses, residual confounding components similar to sedentary conduct and pubertal development standing cannot be excluded. Third, it must be noted that this analysis is a cross-sectional study, so it can not reflect the event and adjustments of PF in adolescents. Given the above limitations, longitudinal studies with more numerous pattern sources and more complete designs are wanted in the future to higher perceive the influencing components of Chinese adolescents’ PF and formulate corresponding countermeasures.
5. Conclusions
This paper elucidates for the first time the impact of DPs and PA on the PF through the issue evaluation of adolescents aged 11–18 years in Shandong Province from 2020–2021, and further analyzes the variations between boys and girls. We have found that: (1) Overweight, unhealthy meals patterns and poor higher body muscular energy have been more frequent in boys than in girls. (2) Highly educated fathers contributed to enhance PF in boys, however extremely educated moms didn’t. (3) Four DPs had been obtained, and totally different DPs might have different effects on PF in girls and boys. Specifically, the unhealthy meals pattern was negatively associated with CRF in boys. After adjusting for energetic PA, the connection between unhealthy meals pattern and girls’ BMI grew to become important. The tuber and legume sample was negatively associated with BMI in girls, but positively associated with flexibility health in boys. The protein and seafood pattern was positively associated with girls’ motor health and boys’ higher body muscular energy. Therefore, in order to successfully improve PF in adolescents, strategy builders ought to take into account the differences in diet and PF between girls and boys as well as the different results of DPs and PA on PF in boys and girls in order to maximize the effectiveness of interventions. Our findings may have benefits in formulate a theoretical basis for the event of PF in Chinese adolescents. Future larger potential studies are needed to discover the connection between DPs, PA and PF and other health-related parameters in the Chinese adolescents.
