Healthy lifestyles and physical fitness are associated with abdominal obesity among Latin‐American and Spanish preschool children: A cross‐cultural study

Summary Background Identifying environmental factors that influence health in children are necessary to develop preventive strategies. Objective To determine the association between the lifestyles of children (i.e., Mediterranean diet (MD), physical activity (PA), fitness and screen time (ST) with abdominal obesity (AO) of preschoolers from three Spanish‐speaking countries (Chile, Colombia and Spain) with different socioeconomic levels and Human Development Index (HDI) indicators. Material and Methods This cross‐sectional study included 982 schoolchildren (aged 4–6 years; 56.8% girls) from Chile (n = 409), Colombia (n = 281), and Spain (n = 292). Body mass index (BMI), waist circumference (WC), waist‐to‐height ratio (WtHR), adherence to the MD, PA, ST and physical fitness were evaluated. Results Spanish preschoolers reported a lower WtHR (p < 0.001), greater physical fitness (Z‐score) (p < 0.001) and higher adherence to the MD (p < 0.001) than their Chilean and Colombian peers. In addition, Colombian preschoolers had a better lifestyle (PA + ST) than their Chilean and Spanish peers (p < 0.001). Chilean preschoolers reported a higher prevalence of AO than the Spanish preschoolers (65% vs. 51.9%; p = 0.001). Conclusion Lifestyle had a significant association with AO among Spanish‐speaking preschool children, with physical fitness especially being a relevant factor regardless of the country of origin. The findings of the current study may support the development of public guidelines focusing on healthy lifestyles in children to create effective plans that contribute to the early treatment of AO in preschool children.


| INTRODUCTION
The prevalence of obesity among children and adolescents (aged 2-18 years) is an important public health problem. 1 In 2020, globally, 38.9 million children under the age of 5 years old were overweight. In this public health problem, about half of all countries have experienced no progress or are worsening. Particularly, childhood obesity in preschoolers is a global phenomenon in developed and undeveloped countries where nutritional deficiencies and environmental factors from the lifestyles of parents can explain part of their children's health, but where other direct lifestyle factors, such as diet and physical activity (PA) can also play a critical role promoting greater energy expenditure. 2 In this regard, it is noteworthy that malnutrition and lower levels of PA increase childhood obesity. 3 Children with obesity show breathing difficulties, increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance, and psychological effects. 3 It should be noted that the preschool age (2-4 years old) is very important in the development of adipose tissue, as it covers the rebound of adiposity. 4 Especially, Abdominal obesity (AO) is associated with increased cardiovascular risk in preschoolers. 5 Mainly, the waist-to-height ratio (WHtR), which is calculated as waist circumference (WC) divided by height, has gained a lot of attention such as an anthropometric index for central adiposity that allows identifying cardiometabolic risk in pre-schoolers, children, youth and adults in different regions around de world. 6 Although the adverse health effects of AO are well recognized in adults, this pattern of relationships remains to be determined in paediatric populations. 7 Therefore, early identification of risk factors associated with overweight/obesity in the preschool population, especially concerning lifestyles, is essential to prevent long-term health consequences.
Although obesity is primarily the result of an imbalance between energy intake and expenditure, 8 the explanations for AO in preschool children are various, including parental obesity (i.e., familial inheritance), screen time (ST) or sedentary behaviour, PA (particularly moderate-tovigorous PA), parents education, birth weight of children, 9 low socioeconomic status of parents, adherence to the Mediterranean diet (MD) or physical fitness, as a consequence of PA patterns. [9][10][11][12] It is noteworthy that changes in the global food system with caloric intake, high periods of low PA, and sedentary time are identified as the main predictors of obesity in preschool children. 4 The food habits of children are determinant factors that influence the development of obesity. 13 There is evidence that adherence to the MD is associated with positive effects on specific components of health, 14 and it has an influence on health in later life. 15 Additionally, better adherence to the MD in preschool children is associated with a lower risk of developing AO in childhood and adolescence. 12 On the other hand, high ST has been associated with a cluster of behavioural risk factors in children, 16 and PA has been indicated as an important factor to maintain physical health 17 due to it being a modifiable factor. 18,19 In this regard, there is an association with low levels of moderate-to-vigorous PA and higher obesity status among preschool children. 8,20 Likewise, physical fitness is considered as an important health marker in early childhood and later in life. [21][22][23] Moreover, it seems important to assess the ability of the respiratory systems, since negative cardiorespiratory fitness (CRF) in these stages is associated with adverse cardiovascular indicators (e.g., hypertension). 24  problem of obesity among their child populations. [31][32][33] Other local studies showed a prevalence of 50.4% and 50% of AO in Spanish and Colombian preschoolers, respectively, but up-to-date information is not available for the entire country. 34,35 Therefore, the purpose of this study was to determine the association between the lifestyles of children (i.e., MD, PA, and ST) with AO of preschoolers from three Spanish-speaking countries (Chile, Colombia, and Spain) with different socioeconomic levels and HDI indicators.
It is expected that the findings from this cross-cultural study will provide practical information on the lifestyles of preschoolers and physical fitness, as well as the prevalence of AO, regarding boys and girls in the three countries.

| MATERIAL AND METHODS
A priori sample size was performed using the G-Power. The inclusion criteria were as follows: (i) presenting informed consent of the parents, (ii) belonging to educational centres, and (iii) being between 4 and 6 years of age. The exclusion criteria were as follow some medical condition such as some neurodevelopmental or neuromotor disability (autism, Down's syndrome), and/or the presence of some disorder associated with the cardiorespiratory and locomotor systems such as asthma, muscle injuries, and so forth. without allowing the dynamometer to touch the body; force is applied gradually and continuously for a maximum of 3-5 s. 37 The test was performed twice, and the maximum score for each hand was recorded in kilograms (kg

| Abdominal obesity
Waist-to-height ratio (WtHR) is a simple, yet effective, a surrogate measure of AO and may be a good predictor of cardiovascular disease risk in children. 10      examine these relationships. The main results were as follows: (1) Chilean children showed a higher prevalence of AO, with significant differences with Colombian and Spanish girls; (2) Chilean children had lower levels of physical fitness than Colombian and Spanish children;

| Statistical analysis
(3) In particular, Spanish preschoolers reported a lower WtHR, a higher adherence to the MD and greater physical fitness than their Colombian and Chilean peers; however, Colombian children showed better lifestyles than their Spanish and Chilean peers.
Physical fitness was the common factor between countries to predict AO. Overall, the current findings add to a growing body of literature in children and adolescents about the relationship between physical fitness and AO, [42][43][44] particularly in preschool children. 45,46 Given that fitness level is a potential biomarker of health from an early age, improvements in physical fitness could be important for the health of preschoolers. 47 Therefore, replacing sedentary time and/or low PA with moderate and vigorous PA in children and adolescents is favourably associated with most markers of cardiometabolic risk. 48 Likewise, stimulating higher intensity PA and reducing sedentary behaviour at a young age may have long-term beneficial effects on body composition and physical fitness in later childhood. 49 In addition, overall bad lifestyle and physical fitness (Z-score) were risk factors for AO only in the Chilean population. According to this, another study conducted on Chilean schoolchildren reported that a bad lifestyle was associated with low physical fitness related to health; additionally, schoolchildren with a good lifestyle had better VO 2 max. 50 In the same way, a bad lifestyle (i.e., ST) was inversely related to the motor skills of preschool children. 51 Conversely, a good lifestyle (i.e., objective measured PA) was positively associated with physical fitness in Chinese preschoolers. 52 In this sense, physical inactivity is recognized as a determinant of low physical fitness in preschoolers. 53 In the present study, 0 In turn, is remarkable that higher adherence to a healthy lifestyle (i.e., PA, sleep time, television time, plant-based foods) at age 4 years decreased the risk of overweight, obesity, and abdominal obesity at age 7 years in Spanish children. 54 Recently, Musálek et al. show that normal weight obesity seems to develop from early childhood and is related to low physical fitness and deficits in eating habits, which might inhibit the natural necessity for PA from the pre-school stage. 55 Moreover, in Spanish preschool children, a previous study found that higher adherence to the MD and higher CRF were associated with lower WtHR. 56 In this regard, the current study indicates that Spanish preschoolers displayed high adherence to the MD, high physical fitness, and a lower WtHR than their Chilean and Colombian peers.
Strangely low adherence to the MD, was a protective factor of AO in the Colombian population. Conversely,there are several studies in children on the relationship between obesity and eating habits. [57][58][59] Children with high adherence to the MD were especially less likely to be overweight or have obesity. 60  The limitations of the present study include those inherent to its transversal character, likewise, the sample was not randomized.