Mediterranean diet and adiposity in children and adolescents: A systematic review

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.

Effects of lifestyle-based interventions to improve Mediterranean diet adherence among the young population: a meta-analysis of randomized controlled trials

CONTEXT

Despite the large number of studies published to date, the effect of lifestyle-based interventions on improving adherence to the Mediterranean diet (MedDiet) in young people has not been meta-analyzed.

OBJECTIVE

The aim of the present systematic review and meta-analysis was two-fold: (1) to determine the pooled intervention effects of lifestyle-based interventions on improving adherence to the MedDiet in a young population aged 3 years-18 years and (2) to examine the potential factors related to those intervention effects.

DATA SOURCES

A systematic search of the MEDLINE (via PubMed), Scopus, Cochrane Library, and Web of Science databases was performed from their inception until June 15, 2023.

DATA EXTRACTION

Different meta-analyses were independently performed to observe the effect of lifestyle-based interventions on adherence to the MedDiet (according to the Mediterranean Diet Quality Index in children and adolescents [KIDMED]).

DATA ANALYSIS

Compared with the control group, the intervention group showed a small increase in KIDMED score (d = .27; 95% confidence interval [CI], .11 to .43; P < .001; I2 = 89.7%). Similarly, participants in the lifestyle-based intervention groups had a 14% higher probability of achieving optimal adherence to the MedDiet (risk difference = .14; 95% CI, .02 to .26; P = .023; I2 = 96.8%). Greater improvements in achieving optimal adherence to the MedDiet were found in interventions delivered out of school (risk difference = .24, 95% CI, .04 to .44; I2 = 88.4%), those aimed at parents or at both children and parents (risk difference = .20, 95% CI, .07 to .34; I2 = 98.2%), and those including only participants with overweight/obesity (risk difference = .34, 95% CI, .15 to .52; I2 = .0%).

CONCLUSION

Healthy lifestyle-based interventions seem to be effective in increasing adherence to the MedDiet and in achieving optimal adherence to this dietary pattern among children and adolescents.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD2022369409.

The Benefits of the Mediterranean Diet on Inflamm-Aging in Childhood Obesity

(1) Background: Numerous elements of the Mediterranean diet (MD) have antioxidant and anti-inflammatory qualities. (2) Methods: We present a narrative review of the potential benefits of the Mediterranean dietary pattern (MD) in mitigating aging-related inflammation (inflamm-aging) associated with childhood obesity. The mechanisms underlying chronic inflammation in obesity are also discussed. A total of 130 papers were included after screening abstracts and full texts. (3) Results: A complex interplay between obesity, chronic inflammation, and related comorbidities is documented. The MD emerges as a promising dietary pattern for mitigating inflammation. Studies suggest that the MD may contribute to weight control, improved lipid profiles, insulin sensitivity, and endothelial function, thereby reducing the risk of metabolic syndrome in children and adolescents with obesity. (4) Conclusions: While evidence supporting the anti-inflammatory effects of the MD in pediatric obesity is still evolving, the existing literature underscores its potential as a preventive and therapeutic strategy. However, MD adherence remains low among children and adolescents, necessitating targeted interventions to promote healthier dietary habits. Future high-quality intervention studies are necessary to elucidate the specific impact of the MD on inflammation in diverse pediatric populations with obesity and associated comorbidities.

Adherence to the Mediterranean Diet in Children and Adolescents and Association with Multiple Outcomes: An Umbrella Review

The Mediterranean Diet (MD) has been linked to numerous health benefits. This umbrella review aims to synthesize evidence from systematic reviews on the MD's impact on children and adolescents aged 6 to 19 years. Following Joanna Briggs Institute guidelines, we included 11 systematic reviews focusing on the MD's effects on health outcomes, such as asthma, anthropometric measures, physical fitness, and inflammatory markers. The results indicate a protective role of the MD against childhood asthma due to its antioxidant-rich components. However, evidence for its impact on allergic conditions like rhinitis and eczema is inconclusive. Findings regarding anthropometric outcomes, particularly BMI, are limited and inconsistent. A positive correlation was observed between MD adherence and increased physical activity, improved physical fitness, quality of life, and reduced sedentary behavior. Additionally, the MD showed an inverse relationship with pro-inflammatory biomarkers, suggesting anti-inflammatory benefits. The inconsistency in BMI findings and the potential anti-inflammatory properties of the MD warrant further longitudinal research. Future studies should explore the MD's impact on cognitive functions, academic performance, and mental health in this age group, highlighting the significance of establishing healthy eating habits early in life.

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.

Lifestyle Behaviours, Self-Esteem and Academic Performance in Primary Education Students-A Structural Equation Model According to Sex and School Type

(1) Background: The present study aimed to examine the relationship between physical activity (PA), screen time (ST), maximal oxygen uptake (VO2max), Mediterranean diet (MD) adherence, self-esteem (SE) and academic performance (AP) in primary education students. In order to address this aim, an explanatory model was developed to examine the existing relationships between PA, ST, VO2max, MD adherence, SE and AP. Further, the proposed structural model was examined via multi-group analysis as a function of sex and school type. (2) Methods: A non-experimental, descriptive, comparative and cross-sectional study was designed with a total sample of 269 Spanish students (11.29 ± 0.62). Validated questionnaires were administered to collect data on study variables. (3) Results: Relative to boys, girls reported better academic grades and showed a stronger positive relationship between MD adherence and AP, MD adherence and PA, and VO2max and SE. Likewise, girls showed a stronger negative relationship between ST and VO2max, and ST and MD adherence. At the same time, mixed funding school (MFS) students reported higher PA engagement than state school (SS) students. However, SS students reported better MD adherence, ST and AP than MFS students. Further, a stronger positive relationship was found in SS students between MD adherence or VO2max and SE than in MFS students. Also, within the former group, ST was more negatively related to MD adherence and VO2max. (4) Conclusions: Scientific and educational communities must develop future strategies that consider potential determinants in order to target more desirable outcomes.

TT Genotype of TLR4 rs1928295 Is a Risk Factor of Overweight/Obesity in Han Chinese Children Aged 7-12 Years and Can Interact with Dietary Patterns to Affect the Incidence of Central Obesity and Lipid Profile, Systolic Blood Pressure Levels

Previous studies have found that TLR4 rs1928295 polymorphism is associated with Body Mass Index in European and American Indian adults. This study evaluates the relationship between this locus polymorphism, obesity-related parameters and dietary patterns in Chinese Han Children. A total of 798 children aged 7-12 years were included in this cross-sectional study. An improved Multiple Ligase Detection Reaction was used for genotyping. Dietary patterns were identified by principal component factor analysis. The overweight/obesity rate of the TT genotype was greater than those of the CC/CT genotype (p = 0.032 and 0.048 in boys and girls, respectively). Boys of the TT genotype could interact with protein and cholesterol intake to increase low density lipoprotein (LDL) levels (p = 0.02, 0.015, respectively), while girls of the TT genotype could interact with total energy intake to increase triglyceride (TG) (p = 0.018) levels. Boys predisposed to a healthy balance dietary pattern (HBDP) and girls predisposed to an egg/fruit/fish dietary pattern (EFDP) were significantly associated with lower rates of central obesity (p = 0.045, 0.028). Boys carrying the TT genotype and predisposed to animal food dietary pattern (AFDP) had a higher level of low-density lipoprotein (p = 0.017) and systolic pressure (p = 0.044). Our results indicated that the TT genotype of TLR4 rs1928295 is a potential risk factor for obesity in Chinese Han children and is associated with dietary patterns.

Mediterranean Diet and Airway Inflammation in School-Aged Children

There seems to exist an intricate relationship between airway inflammation, body mass index (BMI), and diet. The intake of specific foods or food groups has been suggested to suppress the oxidative stress and inflammatory processes that characterize airway inflammation, but little is known about dietary patterns and their complex interplay with BMI and airway inflammation. Therefore, this cross-sectional study aimed to explore the association between adherence to the Mediterranean diet (MD), a characteristic European diet, and levels of airway inflammation in school-aged children, taking into account their BMI. This cross-sectional analysis comprised 660 children: 49.1% females, 7-12 years old. Adherence to the MD was assessed through the alternate Mediterranean score (aMED). Higher scores represent a healthier diet (0-8). Airway inflammation was assessed measuring exhaled fractional nitric oxide (eNO). Two categories of BMI were considered: non-overweight/non-obese (p < 85th) and overweight/obese (p ≥ 85th). The associations between diet and airway inflammation were estimated using logistic regression models. Higher scores of the aMED were associated with decreased odds of having eNO ≥ 35 ppb, but only in non-overweight/non-obese children (OR = 0.77; 95% CI, 0.61-0.97). For overweight/obese children, the previous association was not significant (OR = 1.57, 95% CI, 0.88-2.79). Our findings suggest that adherence to the MD is associated with lower levels of airway inflammation among non-overweight/non-obese children.

Mediterranean Diet-Based Interventions to Improve Anthropometric and Obesity Indicators in Children and Adolescents: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

To our knowledge, no systematic review with meta-analysis has separately synthesized the effects of Mediterranean diet-based interventions in children and adolescents in relation to the effects on anthropometric measures. A better understanding of the effects of Mediterranean diet-based interventions on anthropometric variables could facilitate their implementation in efforts to prevent obesity in the young population. The aim of the present meta-analysis was to evaluate the effects of Mediterranean diet-based interventions on anthropometric and obesity indicators among children and adolescents. Four databases were systematically searched (PubMed, Scopus, Web of Science, and Cochrane Database of Systematic Reviews), including all studies up until 15 March, 2023. Eligible articles were randomized controlled trials measuring the effect of an intervention based on the promotion of the Mediterranean diet and obesity-associated parameters. The effect size of each study was estimated by Cohen's d for continuous variables or risk difference for categorical variables. Compared to the control group, the Mediterranean diet-based interventions showed small and significant reductions in body mass index (d = -0.14; 95% CI: -0.26, -0.01; I2 = 77.52%). Participants in the Mediterranean diet-based interventions had a significant reduction in the percentage of obesity (risk difference = 0.12; 95% CI: 0.01, 0.23; I2 = 84.56%) in comparison with the control group. Interventions had greater effects when aiming at participants with excess weight (that is, overweight or obesity), both for body mass index, waist circumference, waist-to-height ratio, percentage of obesity, and percentage of abdominal obesity. Mediterranean diet-based interventions have a significant effect on reducing the body mass index as well as reducing obesity in children and adolescents (aged 3-18 y). This trial was registered at PROSPERO as CRD42023386789.

The treatment of obesity in children and adolescents: consensus position statement of the Italian society of pediatric endocrinology and diabetology, Italian Society of Pediatrics and Italian Society of Pediatric Surgery

This Position Statement updates the different components of the therapy of obesity (lifestyle intervention, drugs, and surgery) in children and adolescents, previously reported in the consensus position statement on pediatric obesity of the Italian Society of Pediatric Endocrinology and Diabetology and the Italian Society of Pediatrics. Lifestyle intervention is the first step of treatment. In children older than 12 years, pharmacotherapy is the second step, and bariatric surgery is the third one, in selected cases. Novelties are available in the field of the medical treatment of obesity. In particular, new drugs demonstrated their efficacy and safety and have been approved in adolescents. Moreover, several randomized control trials with other drugs are in process and it is likely that some of them will become available in the future. The increase of the portfolio of treatment options for obesity in children and adolescents is promising for a more effective treatment of this disorder.

Health-Related Quality of Life in Childhood and Adolescence: The Interrelation with Level of Adherence to Mediterranean Diet and Dietary Trajectories: Highlights from the DIATROFI Program (2021-2022)

Children's dietary habits can have a key role in contributing to an improvement in their Health-Related Quality of Life (HRQoL). This study aims to assess the connection between Mediterranean diet adherence and HRQoL in a sample of Greek students, utilizing data from the DIATROFI program. The parents of 3774 students (mean age 7.8 (2.6) years) reported their children's HRQoL and level of adherence to the Mediterranean dietary pattern at the beginning and end of the 2021-2022 school year. At baseline, most students' adherence was characterized as moderate (55.2%) or high (25.1%). Students with moderate or high adherence tο the Mediterranean diet were less likely to report a total HRQoL below the median at baseline (OR = 0.56, 95%CI = 0.44, 0.70), along with all its dimensions (physical, emotional, social, and school functions). A one-unit improvement in KIDMED score _{(beginning-end of schoolyear)} was associated with the likelihood of an improvement in total HRQoL _{(beginning-end of schoolyear)} (OR = 1.09, 95%CI = 1.02, 1.17), emotional (OR = 1.09, 95%CI = 1.02, 1.17), and social functions (OR = 1.13, 95%CI = 1.05, 1.22), but not with physical and school functions. The health benefits of the Mediterranean diet in children may not be limited to disease prevention but also extend to their overall wellbeing.

Association between adherence to the Mediterranean diet with anthropometric measurements and nutritional status in adolescents

BACKGROUND

adolescence is a critical period for developing healthy eating habits. It is crucial to evaluate and encourage adherence to the Mediterranean diet, a sustainable and healthy diet model in this age group.

OBJECTIVE

this study aimed to evaluate the relationship between adherence to the Mediterranean diet and anthropometric measurements and nutritional status in Turkish adolescents.

MATERIAL AND METHODS

the demographic characteristics, health information, nutritional habits, physical activity status, and 24-hour dietary recall of the adolescents were obtained with a questionnaire. Adherence to Mediterranean diet was evaluated with the Mediterranean-Style Dietary Pattern Score (MSDPS).

RESULTS

a total of 1,137 adolescents (mean age 14.0 ± 1.37 years) were included; 30.2 % of the boys and 39.5 % of the girls were overweight/obese. The median (interquartile range) value of the MSDPS was 10.7 (7.7), and this value was 11.0 (7.6) for the boys and 10.6 (7.4) for the girls (p > 0.05). The levels of protein, fiber, vitamin A, vitamin C, folate, vitamin B12, iron, magnesium, zinc, and potassium intake increased with adherence to Mediterranean diet (p < 0.001). Age, parental education level, body mass index (BMI), waist circumference, and skipping meals affected MSDPS.

CONCLUSION

adolescents' adherence to the Mediterranean diet was low and correlated with some anthropometric measures. Increasing adherence to the Mediterranean diet may contribute to preventing obesity and adequate and balanced nutrition in adolescents.

Association between Family and School Pressures, Consumption of Ultra-Processed Beverages, and Obesity in Preadolescents: A School-Based Epidemiological Study

The aim of the present work was two-fold. Firstly, to evaluate the association between the consumption of ultra-processed beverages (UPB) on preadolescents’ likelihood of being obese. Secondly, to investigate the potential impact of family and school environmental stressors on this unhealthy lifestyle habit. A cross-sectional study was conducted among 1718 Greek preadolescents and their parents, during the school years 2014 to 2016. Parental and child characteristics were collected anonymously, through self-administered and validated questionnaires. Among others, UPB consumption (soft and flavored drinks) was recorded, classifying children as low, moderate, or high consumers, while anthropometric characteristics [height, body weight, Body Mass Index (BMI)] were also recorded. Almost seven out of ten preadolescents were classified as at least moderate UPB consumers, while approximately three out of ten were classified as high UPB consumers. Higher UPB consumption was associated with significantly higher levels of BMI, while preadolescents living in a more stressful family and school environment were found to consume significantly higher amounts of UPB. Stakeholders should implement programs that raise awareness among parents and teachers about the sources of stress in preadolescence as a potential “triggering factor” of unhealthy dietary preferences.

Association between Food, Beverages and Overweight/Obesity in Children and Adolescents-A Systematic Review and Meta-Analysis of Observational Studies

A healthy diet is essential to prevent childhood obesity, however, adherence to a healthy diet is challenging. The aim of this study was to give a comprehensive overview of the literature investigaating associations between food and beverages and overweight/obesity in children and adolescents in order to identify dietary risk factors. A systematic search was performed in four databases and observational studies were included. Meta-analysis was performed using the random effect model. Sixty records met inclusion criteria and 14 different food or beverage categories were identified. A higher intake of sugar-sweetened beverages increased the odds of overweight/obesity by 1.20 (p < 0.05) (n = 26) and higher intake of fast food increased the odds of overweight/obesity by 1.17 (p < 0.05) (n = 24). Furthermore, higher intake of meat (OR 1.02, p < 0.05 (n:7)) and refined grains (OR 1.28, p < 0.05 (n:3)) was associated with an increased risk of overweight/obesity. In contrast, higher intake of whole grain (OR 0.86, p = 0.04 (n:5)) and more surprisingly sweet bakery (OR 0.59, p < 0.05 (n:3)) was associated with a decreased risk of overweight/obesity. In conclusion, a higher intake of sugar-sweetened beverages and a higher intake of fast food was identified as the primary dietary risk factors for overweight/obesity. Future research is needed to strengthen the generalizability of these results.

Gut microbiota in obesity and related comorbidities in children and adolescents: the role of biotics in treatment

INTRODUCTION

Obesity is a complex pathology, globally spread, with a multifactorial pathogenesis, strictly linked with lifestyle, hormones, genetic and epigenetic factors. Evidence supports that obesity, and its comorbidities, are related to changes in gut microbiota, partially responsible of the modulation of energy metabolism.

EVIDENCE ACQUISITION

Pediatric obesity has been associated with lower bacterial diversity and differences in composition of the gut microbiota, also varying according to the metabolic status of obese subjects. Indeed, differences in distributions and activity of microorganisms in the gut of metabolically healthy and unhealthy obese children have been highlighted.

EVIDENCE SYNTHESIS

Based on human studies, this review aims to discuss gut microbiota alterations in obese children and adolescents and its role in obese-related complications. Moreover, the role of biotics (probiotics, prebiotics, synbiotics and -marginally- postbiotics) has been analyzed as modulator of obesity-related dysbiosis.

CONCLUSIONS

As a conclusion, a deeper knowledge about biotic mechanisms of action would be of great interest to implement the clinical care of children and adolescents with obesity and related comorbidities.

Mediterranean Diet in Developmental Age: A Narrative Review of Current Evidences and Research Gaps

Numerous studies in recent decades have shown that Mediterranean diet (MD) can reduce the risk of developing obesity in pediatric patients. The current narrative review summarizes recent evidence regarding the impact of MD across the different stages of child development, starting from fetal development, analyzing breastfeeding and weaning, through childhood up to adolescence, highlighting the gaps in knowledge for each age group. A literature search covering evidence published between 1 January 2000 and 1 March 2022 and concerning children only was conducted using multiple keywords and standardized terminology in PubMed database. A lack of scientific evidence about MD adherence concerns the age group undergoing weaning, thus between 6 months and one year of life. In the other age groups, adherence to MD and its beneficial effects in terms of obesity prevention has been extensively investigated, however, there are still few studies that correlate this dietary style with the incidence of non-communicable diseases. Furthermore, research on multi-intervention strategy should be implemented, especially regarding the role of education of children and families in taking up this healthy dietary style.

Guide and advances on childhood obesity determinants: Setting the research agenda

Childhood obesity demands global solutions. Low birth weight and small for gestational age were associated with childhood obesity. Available data do not support prenatal exposure to antibiotics as risk factor for childhood obesity, and posology must be assessed. Prenatal exposure to persistent organic pollutants shows associations with childhood obesity. Gut microbiota composition influences obesity onset in childhood. Despite the unquestionable role of Mediterranean diet on healthy weight, there are only incomplete indications of metabolic benefits in childhood weight after following Mediterranean diet. Negative association between total dairy consumption and childhood obesity has been found, but inverse causality could not be discarded. Ultra-processed food intake is an adverse determinant of childhood obesity. Physical inactivity and sedentarism are critical risk factors of children adiposity; hence, built environment and environmental features will be determinants of childhood obesity. A consistent metabolic pattern of childhood obesity was observed; metabolomics research is needed to assess the role of specific molecules concerning childhood obesity. Epigenetic experiences support association with childhood obesity for DNA methylation of specific genes and miRNAs. Therefore, recent childhood obesity rates cannot only be explained by genetic predisposition and changes in lifestyle habits. It implies gene-environment interactions. It will be the next research.