Adherence to Mediterranean Diet Related with Physical Fitness and Physical Activity in Schoolchildren Aged 6-13

Adherence to Mediterranean Diet and Health Outcomes in Adolescents: An Umbrella Review

CONTEXT

Proper nutrition represents 1 of the domains of adolescents' well-being. In this context, the Mediterranean diet (MD), as a healthy, traditional, and sustainable dietary pattern, plays a crucial role in promoting adequate growth and preventing chronic noncommunicable diseases.

OBJECTIVE

The currently available evidence on the effects of adherence to the MD (AMD) in association with several physical health outcomes in adolescence is summarized in this review.

DATA SOURCES

Five electronic databases were searched.

STUDY SELECTION

Systematic reviews with or without meta-analysis of observational studies and randomized clinical trials, published in English during 2013-2022, and that assessed the health impact of AMD among adolescents were eligible.

DATA EXTRACTION

Details on study design, methods, population, assessment of dietary patterns, health outcomes, and main results were extracted.

RESULTS

The search yielded 59 references after removal of duplicates. Applying PICOS criteria, 4 systematic reviews and 3 meta-analyses ultimately were included in this review. The AMD was evaluated in association with overweight/obesity and adiposity in 2 studies, musculoskeletal health in another 2, inflammation in 1 study, and cardiometabolic health in 1 study. The seventh review examined all mentioned health outcomes (overweight and obesity, musculoskeletal health, inflammation, and cardiometabolic health) in relation to AMD.

CONCLUSIONS

Overall, this umbrella review showed limited evidence and a lack of consistency about the relation between AMD and health outcomes of interest in adolescence, indicating the need for more studies to better understand it.

SYSTEMIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023428712.

The moderating effect of gender on physical activity participation and physical fitness in children

Background

The level, direction or presence of the relationship between perceived physical activity (PA) participation and physical fitness (PF) in children may differ by gender and this will assist in designing gender-specific interventions to promote PA participation, which in turn improves PF levels.

Aim

This study aimed to establish the moderating effect of gender on the relationship between perceived PA participation and PF.

Method

A cross-sectional study was conducted with a cohort of 870 primary school children aged 9-14 years old. Perceived PA participation was measured using the PAQ-C questionnaire while PF levels were measured using cardiorespiratory endurance (i.e. VO2 max).

Results

The results showed significant gender differences for perceived PA participation levels (t = -3.40, p ≤ 0.001) and PF (t = -11.59, p ≤ 0.001), with boys reporting higher levels than the girls. Perceived PA participation had a positive, weak and statistically significant correlation with PF (r = 0.251; p ≤ 0.001). Gender significantly moderates the relationship between perceived PA participation and PF (β3 = 3.518; 95% confidence interval [CI]: 0.642 to 6.395; p = 0.017).

Conclusion

The moderating effect of gender on the relationship between perceived PA participation and PF highlights the differences in physiology as well as the societal PA associated roles played by boys and girls.

Contribution

The study has established that the relationship between perceived PA participation and PF is more pronounced among boys than girls.

Predictive approach of health indicators from the physical activity habits of active youth

The aim of this study is to analyse the relationship between sport modalities practiced, physical fitness, body composition, and healthy habits in an active young population, using a statistical model for prediction. A total of 2255 (1528 boys and 727 girls) children and adolescents aged 6-17 years old who were involved in extracurricular sports from rural areas of Spain participated. Physical fitness was assessed through validated field test and, body composition was determinated using bioelectrical impedance analysis. Adherence to the Mediterranean diet was assessed by KIDMED questionnaire. The general sport variable was significant in VO2max when comparing the invasion and combat modalities to the reference level (court/net). The sex and age variables revealed significant differences in all physical fitness and body composition parameters. Health parameters, such as hours of additional practice, adherence to the Mediterranean diet, and previous experience, showed significant differences. The study concludes that the sport modality variables of training, sex, age, and maturational period have an impact on body composition and fitness parameters in this population. Therefore, by focusing on factors associated with lower values in health indicators, we can prevent health problems during adulthood, such as cardiorespiratory deficits.

Factors associated with Mediterranean diet adherence in a sample of high socio-economic status children from southern Spain

OBJECTIVE

The present study examined the association of BMI, fat mass, physical activity engagement (PA), maximal oxygen consumption (VO2max), screen time and academic performance (AP) with Mediterranean diet (MD) adherence in a sample of high socio-economic status (SES) children.

DESIGN

A non-randomised design was used. A multilinear regression model was developed using backward elimination. Analysis included variables pertaining to age, BMI, VO2max, fat percentage, AP, PA engagement and screen time. All participants had a high SES and so this variable was not included as a predictor. Data met the assumptions required for multiple regressions in terms of linearity, homoscedasticity, normality, independence and non-multicollinearity.

SETTING

Two state and three mixed funding schools in Granada, Spain.

PARTICIPANTS

Data were collected from 244 children aged between 10 and 12 years.

RESULTS

Better AP, higher PA engagement and lower screen time were found to be predictive of MD adherence. These variables explained 22·9 % of the variance in data measuring adolescent MD adherence.

CONCLUSIONS

The present study suggests that, in addition to SES, PA, AP and screen time are important components to consider when targeting improvements in MD adherence in children. It is, therefore, concluded that interventions targeting improvements in PA, AP and screen time are needed to promote MD adherence in children, regardless of SES.

Comparison of Adherence to Mediterranean Diet between Spanish and German School-Children and Influence of Gender, Overweight, and Physical Activity

BACKGROUND

Poor dietary habits and low levels of physical activity (PA) have a strong tendency to track from childhood into adulthood. The Mediterranean Diet (MD) is known to be extremely healthy, associated with lower BMI and a lower risk of obesity in children and adolescents. Therefore, adherence to the MD was compared between Spanish (n = 182) and German (n = 152) children aged 10 to 13 years to examine a possible more "westernized" diet in Spain with a non-Mediterranean country, that traditionally prefers a "Western diet" and to determine the association between adherence to the MD and gender, body composition, and PA levels.

METHODS

In the German observational longitudinal cohort study and the Spanish cohort study, body composition and questionnaires (KIDMED, Diet Quality (IAES)) were obtained, and accelerometers (Actigraph) were applied to detect PA.

RESULTS

Girls had higher BMI-standard deviation score (SDS) than boys and Spanish girls were less active than boys. Differences were detected in MD habits, such as favorable fruit-, vegetables-, fish-intakes, and dairy products in Spanish children and unfavorable consumptions of fast food, processed bakery goods, candies, and sweet beverages in German children. Independently of country, girls, children with lower BMI-SDS and children with higher PA level were related with better diet quality.

CONCLUSION

Spanish children showed higher adherence to MD and diet quality (IAES) compared to German children, but there was a trend toward a more "westernized" diet. Gender, body composition, and PA influenced nutrition regardless of country.

Association between Dietary Patterns and Physical Fitness among Chinese Children and Adolescents in Shaanxi Province

Background: This study aims to investigate the associations between dietary patterns (breakfast, egg, dairy products, and sugared beverage intake frequencies) and physical fitness among Chinese children and adolescents in Shaanxi Province. METHODS: Data were extracted from the Chinese National Survey on Students’ Constitution and Health (CNSSCH). The study ultimately included 7305 participants (48.4% male, 51.6% female) aged 6–22 in Shaanxi Province, China. Multiple linear regression was used to examine the association of the frequency of breakfast, egg, dairy product, and sugared beverage intakes with physical fitness. RESULTS: The frequency of breakfast, egg, and dairy product intakes were all independently and positively associated with the level of physical fitness. The frequency of sugared beverage intake was negatively associated with the level of physical fitness. CONCLUSION: Healthier dietary patterns (i.e., higher breakfast, egg, and dairy product intakes and lower sugared beverage intake) were associated with greater physical fitness. Specifically, maintaining a healthy dietary pattern of breakfast, egg, and dairy product intakes can positively affect the strength and endurance performance of children and adolescents. Increased dairy product intake plays a crucial part in boosting the physical fitness total scores of children and adolescents.

Early Life Factors Associated with Lean Body Mass in Spanish Children: CALINA Study

Early life is critical for the programming of body composition. The literature links perinatal factors with fat mass development and its future effects (e.g., obesity); however, little evidence exists between early life factors and lean body mass (LBM). This study follows up on a cohort of 416 Spanish children at ages six to eight, previously evaluated at birth in the CALINA study. Here, we studied the association between early life factors, LBM, and limb strength. Parental origin/nutritional status, maternal smoking during pregnancy, gestational diabetes/weight gain/age, birth weight (BW), early feeding, and rapid weight gain (RWG) were collected from primary care records. Bioimpedance analysis, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and a handgrip/standing long jump test were used to assess fat-free mass index (FFMI), total lean soft tissue mass index (TLSTMI), muscle cross-sectional area index (MCSAI), and limb strength, respectively. In girls, maternal smoking, gestational age, and BW were positively associated with FFM/LSTM. In boys, the parents’ BMI, BW, and RWG were positively associated with FFM/LSTM. BW was associated with handgrip strength in both. Maternal BMI in girls and RWG in boys were negatively associated with the standing long jump. Early life programming plays a key role in determining LBM in children.

Cognitive and Physical Effects of Warm-Up on Young Soccer Players

This study analyzed the effects of with (WC) or without conducting a warm up on youth soccer players immediately before performing physical and cognitive tests. Fourteen youth soccer player (age 11.64 ± 0.50) participated in a counterbalanced cross-sectional study in which three conditions were tested: (a) basal lineal condition; (b) WC (immediately before the physical and cognitive tests); and (c) without WC (passive resting for 15 min between the warm-up and physical and cognitive tests). A 30-m sprint test, countermovement jump, and psychomotor vigilance task were also applied. The WC revealed significant improvements in countermovement jump (p < .05), 30-m sprint test performance (p < .05), and reaction time in psychomotor vigilance task (p < .05) in comparison to basal lineal condition and without WC. A 15-min rest after a warm-up has a meaningfully decremental effect on the physical and cognitive readiness of youth soccer players, in comparison with when they warm-up immediately before the demands are imposed.

Determinants of Adherence to the Mediterranean Diet in Spanish Children and Adolescents: The PASOS Study

A progressive shift away from traditional healthy dietary patterns, such as the Mediterranean diet (MedDiet), has been observed in recent decades. The aim of this study was to assess determinants of optimal adherence to the MedDiet in Spanish children and adolescents. A cross-sectional analysis was included in the PASOS nationwide representative study in Spain. Participants were 3607 children and adolescents; 8-16 years old. Primary and secondary outcome measures of weight and height were measured. Adherence to the MedDiet, physical activity, and sedentary behavior in children and adolescents, as well as parental physical activity and dietary habits, were assessed. Optimal adherence to the MedDiet was observed in 45.5% of primary school students and 34.8% of secondary school students (OR: 0.65; 95%CI: 0.56-0.75). Optimal adherence to the MedDiet was higher in children/adolescents meeting daily recommended moderate and vigorous physical activity (OR: 2.39, 95%CI: 1.97-2.89) and in those meeting daily recommended screen time on weekdays (OR: 2.05, 95%CI: 1.77-2.38) and weekends (OR: 1.76, 95%CI: 1.48-2.10). Participants with optimal adherence to the MedDiet were more likely to have mothers with a high-level education and high-tercile of SDQS, mothers who never smoked or were former smokers, and mothers who met the recommended physical activity and screen time. It can be concluded that a low prevalence of optimal adherence to the MedDiet was found among current Spanish children and adolescents. Optimal adherence to the MedDiet was associated with reaching the recommendations on physical activity and screen time, with the highest maternal educational level, and healthier maternal lifestyles.

Mediterranean diet quality index is associated with better cardiorespiratory fitness and reduced systolic blood pressure in adults: A cross-sectional study

BACKGROUND

Literature suggests higher cardiorespiratory fitness (CRF) is inversely related to chronic diseases such as metabolic syndrome and cardiovascular disease and hypertension. The aim of this study was to assess the association of Mediterranean dietary quality index (Med-DQI) with CRF and hypertension in a sample of Iranian adults.

METHODS

This was a cross-sectional study on 270 healthy men and women, aged 18-45 years. Dietary intake and physical activity level were assessed through a validated food frequency questionnaire (FFQ); and the International Physical Activity Questionnaires (IPAQ), respectively. Cardiorespiratory fitness was assessed by using a graded exercise treadmill test. The association between Med-DQI and CRF was investigated using multiple regression models.

RESULTS

Participants in the top tertiles of Med-DQI, had higher VO2 max (mL/kg/min) (p = 0.02) and lower SBP (p = 0.01). When we controlled for age, sex, weight, smoking, physical activity and energy intake, the significant results were remained. Results of unadjusted linear regression shows that CRF was positively associated with cholesterol (p < 0.001) and fish (p < 0.001). Also, CRF was positively associated with vegetables and fruits (p < 0.001) and olive oil (p = 0.05). After adjustments for confounders, the significant associations of olive oil and cholesterol with CRF were disappeared while vegetables and fruits and total score of Med-DQI remained significant. There were no significant relations between saturated fatty acids meat, and cereals with Med-DQI.

CONCLUSIONS

Our results demonstrated that Med-DQI was associated with better CRF in Iranian adults and SBP. Further studies with interventional approaches are needed to better clarify the causal inference of these associations.

Healthy and Sustainable Dietary Patterns in Children and Adolescents: A Systematic Review

The need for adherence to a healthy and sustainable dietary pattern in the pediatric stage is discussed worldwide, being linked to a progressive incidence of noncommunicable diseases in adulthood. The aims of this systematic review were to summarize the healthy and/or sustainable dietary patterns, defined a priori, described in the literature for use during the pediatric stage; to evaluate the adherence to these dietary patterns; and identify the health-related benefits associated with adherence to these patterns. A literature search was carried out on Medline, Scopus, and Web of Science from 2010 up to 2021, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 128 articles were included according to the following criteria: participants 2-17 y old, healthy and/or sustainable dietary patterns defined by an a priori methodology; articles written in English or Portuguese; and published since 2010. Fifty instruments with 14 adaptations that measure adherence to healthy and/or sustainable dietary patterns in children and adolescents were found. The Mediterranean Diet was the most studied dietary pattern. Adherence to healthy and/or sustainable dietary patterns has wide variations worldwide. Most of the instruments described have been little studied at pediatric ages, reducing the ability to extrapolate results. Higher adherence to these dietary patterns was associated with lower body fat, waist circumference, blood pressure, and metabolic risk. There is no consensus regarding the association with BMI. No studies have proofs of the sustainability characteristics of these instruments, it being necessary to produce a new sustainable instrument or test the association of the previous ones with, for example, the ecological footprint. Further validations of these instruments in each country and more prospective studies are needed to establish temporal relations with health-related outcomes. This systematic review was registered at www.crd.york.ac.uk/prospero/ as CRD42020221788.

Adherence to the Mediterranean Diet and Its Association with the Level of Physical Activity in Fitness Center Users: Croatian-Based Study

The Mediterranean diet (MD) is based on the traditional cuisine of south European countries, and it is considered one of the healthiest dietary patterns worldwide. The promotion of combined MD and physical activity has shown major benefits. However, the association between physical activity and the MD in regular fitness center users is still insufficiently investigated. This cross-sectional survey-based study was conducted on 1220 fitness center users in Croatia. The survey consisted of three parts: general information, the Mediterranean Diet Serving Score (MDSS) and the International Physical Activity Questionnaire Short Form (IPAQ-SF). The results showed that 18.6% of fitness center users were adherent to the MD, and there was a significant positive correlation between the level of physical activity and the MDSS score (r = 0.302, p < 0.001). Moreover, after dividing the sample into tertiles based on the IPAQ-SF score, the third tertile (MET > 3150 min/wk) had the most fitness center users (34.4%) adherent to the MD, while the first tertile (MET < 1750 min/wk) had the least (6.1%). These outcomes emphasize the importance of physical activity as they imply that, with higher levels of physical activity, people are also possibly more aware of the importance that a healthy and balanced diet has on their well-being.

Associations between Spanish children's physical activity and physical fitness with lean body mass: The CALINA study

The present study investigated the associations between physical activity (PA) and physical fitness (PF) with lean body mass (LBM) and evaluated whether PA mediates the association between PF and LBM. 279 children (150 boys) aged 7.5 ± 0.3 years participated in the study. PA was assessed by accelerometry and PF with handgrip and the standing long jump test. Total lean soft tissue mass index (TLSTMI), muscle cross-sectional area index (MCSAI), and fat-free mass index (FFMI) were evaluated using dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and bioimpedance analysis, respectively.Total (β = 0.247) and vigorous PA (β = 0.143) were associated with TLSTMI in girls. In boys, total (β = 0.337), light (β = 0.290), vigorous (β = 0.200), and moderate-vigorous PA (β = 0.189) were associated with TLSTMI. Total PA was associated with FFMI (β = 0.299). Handgrip strength does not mediate the relationship between total PA and TLSTMI. Positive associations were found between handgrip strength and TLSTMI, MCSAI, and FFMI in both girls and boys.In children, there is a positive association between total and vigorous PA with TLSTMI. Handgrip strength does not mediate the relationship between total PA and TLSTMI. It was associated with TLSTMI, MCSAI, and FFMI.

Lifestyle mediates the relationship between self-esteem and health-related quality of life in Chilean schoolchildren

A healthy lifestyle, including food habits, physical activity (PA) and screen time (ST), is an important factor for well-being. The main purpose of this study was to analyze the association between lifestyle (i.e., PA, ST and food habits), self-esteem and health-related quality of life (HRQoL). A second objective was to determine the association between self-esteem with HRQoL, considering the mediating effect of lifestyle. A descriptive and cross-sectional study was performed, involving both girls (n = 282, 11.86 ± 0.82 years) and boys (n = 352, 12.02 ± 0.87 years). Lifestyle, self-esteem, HRQoL and anthropometrics parameters were evaluated. The study reported that self-esteem (β; 0.04, P = 0.49) and PA (β; 1.15, P < 0.001) had positive association with HRQoL. By contrast,ST was linked in an inverse way to HRQoL (β; -1.82,, P < 0.001). According to the second objective, self-esteem had a significant association with HRQoL (total effect = 0.48, p < 0.01), and ST mediated this association negatively, instead, PA and food habits positively mediated this association. In conclusion, self-esteem presented association with HRQoL and lifestyle mediates this relationship positively (PA, MD adherence) and negatively (ST). Therefore, promoting healthy lifestyle among children should be a target of community- and school-based interventions to promote well-being.

Is adherence to the Mediterranean diet associated with healthy habits and physical fitness? A systematic review and meta-analysis including 565 421 youths

The relationship between adherence to the Mediterranean diet (MD), physical activity (PA), sedentary behaviour and physical fitness levels has been analysed in several studies; however, there is mixed evidence among youth. Thus, this study aimed to meta-analyse the associations between adherence to the MD, PA, sedentary behaviour and physical fitness among children and adolescents. Three databases were systematically searched, including cross-sectional and prospective designs with a sample of healthy youth aged 3–18 years. Random effects inverse-variance model with the Hartung–Knapp–Sidik–Jonkman adjustment was used to estimate the pooled effect size (correlation coefficient (r)). Thirty-nine studies were included in the meta-analysis, yielding a total of 565 421 youth (mean age, 12·4 years). Overall, the MD had a weak-to-moderate positive relationship with PA (r 0·14; 95 % CI 0·11, 0·17), cardiorespiratory fitness (r 0·22; 95 % CI 0·13, 0·31) and muscular fitness (r 0·11; 95 % CI 0·03, 0·18), and a small-to-moderate negative relationship with sedentary behaviour (r –0·15; 95 % CI –0·20, –0·10) and speed–agility (r –0·06; 95 % CI –0·12, –0·01). There was a high level of heterogeneity in all of the models (I2 ≥ 75 %). Overall, results did not remain significant after controlling for sex and age (children or adolescents) except for PA. Improving dietary habits towards those of the MD could be associated with higher physical fitness and PA in youth, lower sedentary behaviours and better health in general.

The association between healthy lifestyle score with cardiorespiratory fitness and muscle strength

OBJECTIVE

The association of individual behaviours such as diet, tobacco use, body mass index (BMI) and physical activity have been investigated separately in relevance to cardiorespiratory fitness (CRF) and muscle strength. The purpose of this study is to investigate the combined association of the four mentioned lifestyle factors with cardiorespiratory fitness and muscle strength.

METHODS

This cross-sectional study was conducted on 271 Iranian adults, aged 18-70 years. We developed a healthy lifestyle score (HLS) that ranged from 0 to 103 (higher score reflecting better adherence to healthier lifestyle) and included four lifestyle behavioural components (diet, physical activity, smoking and BMI). The relationship between HLS, CRF and muscle strength was determined using linear and non-linear regression analysis.

RESULTS

HLS score was not significantly associated with VO2max (mL/kg/min) P = .43; VO2max (L min) P = .14; VO2max (LBM) (P = .79) and mean muscle strength (MMS) (kg) (P = .11), muscle strength of right hand (MSR) (kg) (P = .10) and muscle strength of left hand (MSL) (kg) (P = .16) in the unadjusted model. After adjustment for potential confounders, we found a significant association between HLS and Vo2max (L/min), MMS (kg), MSR (kg) and MSL (kg) (P < .001 for all). Also HLS and MMS (r = .06, P = .31), MSR (r = .07, P = .25), MMS (r = .05, P = .39), VO2max (mL/kg/min) (r = .01, P = .77), VO2max (L min) (r = .05, P = .35) and VO2max (LBM) (r = .002, P = .91) have no statistically significant linear relationship.

CONCLUSION

Adherence to healthy lifestyle may be associated with increased CRF and muscle strength after adjusting for potential confounding variables.

Adherence to the Mediterranean diet, level of physical activity and body dissatisfaction in subjects 16-50 years old in the Region of Murcia, Spain

OBJECTIVE

To analyze obesity, level of adherence to the Mediterranean diet, physical activity and body dissatisfaction in people aged 16-50 years in the Region of Murcia, Spain.

METHOD

Descriptive and cross-sectional study. A total of 85 people (58 men) aged 16 to 50 years (28.68± 8.846) from 3 sports centers with similar sociodemographic characteristics participated in the study. Anthropometric values were recorded. They were tested for adherence to the Mediterranean diet, International Physical Activity Questionnaire (IPAQ) and test for dissatisfaction with their body (BSQ) and it was statistically related.

RESULTS

It can be seen that the level of physical activity of both men and women is low, according to the IPAQ questionnaire, the men presented a METs/min per week of 3,687.9 (DT=3,137.2) significantly higher than women's. In body dissatisfaction we see that women's concern with their bodies (59.3%) is greater than men's (31%), with a statistically significant difference (P=0.013). Eating habits and BMI do not have statistically significant differences according to sex. When applying the Mediterranean diet adherence test, it is observed that 95.3% of those with weight overload have a medium or low score, and only 4.7% have a discharge score (P=0.128). Those with weight overload have a score of 2,935.73 MET/min per week (DT=2,633.16) and those without weight overload have a value of 3,826.73 (DT=3,164.93, P=0.268). There are significant differences regarding the values of body dissatisfaction. The level of concern of those with weight overload is 53.5%, compared to those without weight overload who have a level of concern of 26.2% (P=0.014).

CONCLUSIONS

Weight overload is associated with body dissatisfaction and a low score in the test of adherence to the Mediterranean diet in people aged 16-50 years. The concern about body image in women was 59.3%.

Relationship Between the Practice of Physical Activity and Physical Fitness in Physical Education Students: The Integrated Regulation As a Mediating Variable

The practice of physical activity (PA) contributes to the prevention of chronic diseases such as obesity, metabolic syndrome or cardiovascular diseases, being also directly related to the individual’s physical fitness. Therefore, it is necessary to measure and monitoring the levels of PA in childhood and adolescence, since it may be useful to describe their current health status and the association with physical fitness, as well as to reveal putative consequences in the future. Within the educational field, it has been shown that physical education (PE) classes are a favorable context for the creation of healthy physical-sports habits and self-determined motivation could be a key for explaining the level of PA practice. For this reason, the purpose of this research was to study the mediating role of integrated regulation (IR) on the relationship between PA and physical fitness in children and adolescents. A total of 325 students between 11 and 14 years old participated in the study. The level of PA was estimated through the specific Physical Activity Questionnaire for Children (PAQ-C), while motivation and IR were measured by using the Perceived Locus of Causality scale (PLOC-2). In addition, physical fitness was measured through the Eurofit fitness battery of tests, composed of three body composition measures and seven tests of different physical capacities. The physical fitness score showed no differences when genders were compared. After regression analysis, the resulting models revealed a good adjustment and correlation between PA practice and physical fitness (β = 0.173; p < 0.001), being established through the macro Process that this relationship is partially conditioned by the IR (β = 0.122; p = 0.03). ROC curve analysis estimated the score of 5.88 as a cut-off point to discriminate between levels of IR for students, classified as physically active or not (AUC = 0.67; p < 0.001). The conclusions from these main and other complementary analyses reporting complete mediations, suggest that the IR could be decisive in predicting and explaining the relationship between the practice of PA and physical fitness at these ages, highlighting its importance for a greater adherence to the practice.

Weight Status Is Related to Health-Related Physical Fitness and Physical Activity but Not to Sedentary Behaviour in Children

Purpose: The aim of this research was to describe, examine, and compare the level of physical fitness, physical activity, and sedentary behaviour in pupils aged 6-13 in the Region of Murcia, Spain, in accordance with weight status. Methods: A total of 370 children (166 girls and 204 boys) aged 6-13 (M = 8.7; DT = 1.8) from the Region of Murcia participated in this descriptive and cross-sectional study. Some anthropometric parameters such as body mass index, waist circumference, as well as skinfold measurements were determined. ALPHA-FIT Test Battery was used to evaluate physical fitness. Krece Plus Short Test was used to measure physical activity level and sedentary behaviour. Results: 52.4% of the children presented excess weight (according to the World Health Organization growth references). Regarding boys, statistically significant differences were found for cardiorespiratory fitness (p < 0.001), relative handgrip strength (p < 0.001), lower muscular strength (p < 0.001), speed-agility (p < 0.001), as well as sport activities hours (p = 0.001) among the three weight status groups (normal weight, overweight, and obesity). As for girls, statistically significant differences were found for cardiorespiratory fitness (p = 0.004), relative handgrip strength (p < 0.001), lower muscular strength (p < 0.001), sport activities hours (p = 0.005), as well as physical activity level (assessed by Krece Plus Test) (p = 0.017). A negative statistically significant correlation was found between body mass index and cardiorespiratory fitness (rho = -0.389), lower muscular strength, (rho = -0.340), and relative handgrip strength (rho = -0.547). At the same time, a positive statistically significant relationship between body mass index and the time spent in speed-agility (rho = 0.263) was shown. Regarding waist circumference and body fat percentage, similar relationships were identified. Moreover, a greater probability of having higher cardiorespiratory fitness (OR = 1.58; CI_95% = 1.38-1.82), relative handgrip strength (OR = 1.25; CI_95% = 1.19-1.31), more hours of sport activities (OR = 1.40; CI_95% = 1.19-1.66), and physical activity level (assessed by Krece Plus Test) (OR = 1.23; CI_95% = 1.07-1.42) was noted in the normal weight group. Conclusions: Children that presented normal weight achieved higher results for health-related physical fitness and physical activity than those with excess weight; this was, however, not found to be the case for sedentary behaviour. The authors emphasise the need for changes in public policies and school-based intervention programmes to develop higher levels of both PF and PA in overweight and obese children.

Relationship between Adherence to the Mediterranean Diet and Body Composition with Physical Fitness Parameters in a Young Active Population

The current study aimed at analyzing the relationship between body composition, adherence to the Mediterranean diet (MD), and physical fitness (PF) in a young active population. A total of 1198 athletes (boys = 875; girls = 323) enrolled in different municipal sports schools participated in this study. Data on adherence to the MD (KIDMED questionnaire), anthropometric measurements, and PF (20 m shuttle run test, handgrip strength, vertical jump and forced spirometry) were collected. Results show that the pubertal boys had a higher score in the KIDMED test than the prepubertal ones (+0.38, p = 0.28). Moreover, boys with better adherence to the MD had significantly higher results in handgrip strength (+12.20 regarding low MD group and +9.13 regarding medium MD group, p < 0.05), as well as in forced vital capacity (FVC) (+0.66 regarding low MD group and 0.29 regarding medium MD group, p < 0.05). No differences were found in the girls. Finally, the result of the KIDMED test is a variable with a positive and significant relationship with cardiorespiratory fitness, along with the FVC, percentage of fat mass, and performance in the vertical jump (p < 0.05). It is concluded that adherence to the MD could show a relationship with various PF variables in boys and could be a predictor of cardiorespiratory fitness in both cases.