Obesity, Metabolic Syndrome, and Nutrition (N&G 2024)

Introduction 

Obesity is a major public health problem that affects more than 300 million children worldwide. Childhood obesity has negative effects on physical and mental health and tends to persist in adulthood, carrying an increased risk of morbidity and mortality. The development of obesity relates to the combined influence of genetic susceptibility and environmental factors, such as sedentary lifestyle and high caloric diet. 

Early life environment can have lasting effects on the physiology and metabolism of the fetus. In utero exposure to maternal adverse conditions is associated with the early meta- bolic programming of human health. Both small and large for gestational age infants have been linked to an increased risk of later cardiometabolic diseases. Maternal obesity during pregnancy is associated with an increased risk of obesity and metabolic disease in the offspring. Also, maternal diet during pregnancy might influence offspring’s predisposition to obesity and diet choice. Some studies reviewed in this chapter evaluate several in utero exposures such as maternal weight, maternal diet and maternal intake of ultra-processed food during pregnancy, and their association with the subsequent development of childhood obesity and metabolic risk of the offspring. Another study assessed the impact of fish oil supplementation of mothers with overweight or obesity during pregnancy on infant body composition and metabolic effects on the offspring. 

Nutrition during the first years of life also has a significant impact on lifelong health. Exclusive breastfeeding is recommended for the first 6 months of life to promote adequate infant growth and development. Breastfeeding has been suggested as a preventive measure against obesity. One of the reviewed studies found that exclusive breastfeeding for at least 4 months has a protective role both for postpartum maternal weight gain and against childhood overweight and obesity. Another study evaluated the “early protein hypothesis,” suggesting that higher protein intake in the first year(s) of life enhances adipogenic activity. In addition, a randomized controlled trial reported the results of using a novel starting infant formula with reduced protein content and lower casein to whey protein ratio compared to a standard formula on weight gain and body composition of infants up to 6 and 12 months. 

Other studies tried to evaluate the impact of the diet composition during later childhood on adiposity. A healthy diet during childhood is fundamental for healthy growth and for the prevention of developing diseases later in life. As the association between dietary diversity and childhood obesity remains unclear, one of the studies was conducted to analyze the effects of dietary diversity on childhood obesity. 

Sugar-containing ultra-processed food and beverage consumption has increased globally in recent years and contributes to the rising global trends of obesity. One of the reviewed studies reported that changes in diet from low to higher dairy consumption and from sugar-sweetened beverages to noncaloric beverages or flavored milk resulted in favorable changes in body composition among children and adolescents. 

Children with obesity are prone to develop obesity-related comorbidities including metabolic syndrome. The association between oral intake of omega-3 fatty acids and metabolic syndrome in adolescents is reported in one of the studies. 

Finally, considering the deleterious consequences of obesity in childhood, public health interventions are urgently called to take nutritional measures with policies that encourage healthy eating among infants and children. 

In this year’s edition of the yearbook chapter focused on the relation between nutrition, obesity, and metabolic comorbidities from infancy to childhood and young adulthood, we selected 12 notable articles from many meritorious manuscripts published in the past year between July 2022 and June 2023. 

Maternal Diet during Pregnancy and Risk of Childhood Obesity  

Maternal consumption of ultra-processed foods and subsequent risk of offspring overweight or obesity: results from three prospective cohort studies 

Comments: One of the potential contributors to the obesity epidemic among children and young people is the unhealthy Western diet characterized by increased consumption of ul- tra-processed foods. These foods generally have higher sugar, sodium, and saturated fat content compared with less processed foods. 

Previous data reported the link between ultra-processed food intake and excess body fat and obesity in adults and children [1, 2]. Mounting evidence suggests that maternal diet influences pregnancy and birth outcomes, but its contribution to childhood obesity has not yet been definitively characterized. Chen et al. [3] reported that low-quality maternal antenatal diet may adversely influence offspring body composition and obesity risk. The current study assessed whether maternal ultra-processed food intake during peripregnancy and during the child-rearing period is associated with offspring risk of overweight or obesity during childhood and adolescence. A potential mechanism by which peripregnancy ultra-processed food intake could affect offspring adiposity includes epigenetic modification of offspring’s susceptibility to obesity. The findings of the study were that peripregnancy consumption of ultra-processed foods was not significantly associated with an increased risk of overweight or obesity in offspring when comparing the group with the highest ultra-processed food intake with the group with the lowest intake. However, maternal consumption of ul- tra-processed food during the child-rearing period was associated with an increased risk of overweight or obesity in offspring, independent of maternal and offspring lifestyle risk factors. This observation suggests that maternal ultra-processed food consumption during child rearing might have a stronger association with offspring obesity than peripregnancy ultra-processed food consumption. 

The study strengths include the data that were based on three prospective cohort studies including a large number of participants with long-term follow-up from pre-conception among mothers and through childhood and adolescence of offspring, and also the use of standardized questionnaires covering a wide range of socioeconomic, lifestyle, and other health risk factors, and the use of detailed dietary assessments using validated food frequency questionnaires. The study used the NOVA classification system (based on the nature, purpose, and extent of food processing: un-processed or minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed foods) [4] to distinguish ultra-processed foods from other foods, which provides robust epidemiological evidence for the role of maternal ultra-processed food consumption in the development of childhood obesity. 

The study limitations include the self-reported diet and weight measurements that might be subject to misreporting. Mothers included were predominantly white and were of comparable socioeconomic backgrounds, which could restrict study gener- alizability. 

In conclusion, the data of the study support the importance of addressing and improving dietary recommendations for women of reproductive age with the aim to improve the health of the offspring. 

Fish oil supplementation during pregnancy and postpartum in mothers with overweight and obesity to improve body composition and metabolic health during infancy: a double-blind randomized controlled trial 

Comments: Obesity in pregnancy is associated with systemic inflammation and exaggeration of the normal insulin resistance that develops in the second half of pregnancy, which leads to excess delivery of lipid and glucose to the fetus. This underlies greater birth weight and body fat in the offspring and is associated with alterations in gene expression mediated by epigenetic changes that increase risk of metabolic dysfunction and disease in later life. Interventional strategies during pregnancy are a potential approach to alleviate and/or prevent obesity and obesity-related metabolic alterations in the offspring. Therefore, an anti-inflammatory and insulin-sensitizing treatment during pregnancy could be of great benefit to the metabolic and body composition- al phenotype of the offspring. 

Fish oil (FO), rich in omega-3 polyunsaturated fatty acids, exerts metabolic health benefits. The use of an omega-3 polyunsaturated fatty acid supplement was previously reported to improve insulin sensitivity [5]. Thus, the researchers of the current study hypothesized that supplementation during the second half of pregnancy and postpartum of overweight and obese women may help prevent the development of greater adiposity and metabolic dysfunction in children. However, they showed no effects of FO supplementation compared with olive oil supplementation on infant body fat percentage at age 2 weeks, and FO-supplemented infants had a higher body mass index Z-score and ponderal index at age 3 months. Although FO supplementation lowered significantly maternal triglycerides by 17% at 30 weeks of pregnancy and infant triglycerides by 21% at 3 months of age, it did not affect maternal or infant insulin resistance. 

The study strengths are the double-blind randomized controlled design and the accurate measurement of body composition (body fat percentage) by dual-energy X- ray absorptiometry scan. 

The study limitations include the treatment that was initiated from midpregnancy, and not preconception or throughout the entire duration of pregnancy, which may impact the results. We can assume that earlier supplementation may improve infant body composition. In addition, the relatively short period of follow-up of infants (only 3 months) does not allow to draw conclusions of the impact of FO supplementation during early childhood. 

Nevertheless, there is a need to follow up the offspring throughout later in life to determine whether the observed metabolic effects persist and to evaluate potential long-term effects of FO supplementation on body composition. 

Maternal pre-pregnancy nutritional status and infant birth weight in relation to 0–2 year-growth trajectory and adiposity in term Chinese newborns with appropriate birth weight-for-gestational age 

Commets: The first 1,000 days of life, from conception until a child’s second birthday, is a window of opportunity for promoting long-term health and well-being. Failure to meet nutritional needs in this period is strongly related to a statistically significant increased lifelong risk of obesity and non-communicable diseases. The key role of diet-related interventions during this crucial phase of growth can be ascribed to at least three mechanisms operating at different levels. First, unmet demands in this critical phase of early development can affect the size and structure of organs, increasing the risk of developing hypertension, cardiovascular disease, type 2 diabetes, and obesity. Extensive growth and neurodevelopment take place in this period, and optimal development depends on the amount and quality of food and nutrients provided. Second, adverse nutritional conditions may permanently affect gene expression and program the body toward the development of noncommunicable diseases. Third, dietary preferences and food habits are formed early in life, influenced by feeding practices of parents and others, the variety of foods offered, and the socioeconomic, cultural, and educational context of the family. Although these factors have been largely reported in children born both small and large for gestational age [6], few studies have focused on those children born with appropriate birth weight for gestational age (AGA). Therefore, in this prospective cohort study, authors examined differential growth trajectories in the first 2 years by considering pre- and perinatal factors among AGA new-borns. Results showed that AGA infants manifest differential growth trajectories by 

the combination of birth weight for gestational age and maternal body mass index. In fact, AGA infants with a combination of high birth weight tertile and maternal obesity/overweight identify a subset of subjects with elevated adiposity among AGA infants. In addition, excessive gestational weight gain was associated with higher values in all adiposity measures in AGA children at 2 years of age. Thus, this finding underscores that AGA term-born infants, who represent the majority of newborns, are heterogenous in their future risk of overweight and obesity and present opportunities for early intervention to prevent obesity. It is remarkable because infants born with AGA consist of ∼80% of newborns. Thus, assessing factors in this large percentage of children refine infant obesity risk assessment at postnatal care for AGA infants during early childhood. Finally, evidence from this study supported the hypothesis that obesity prevention should start prior to conception and concurrently address multiple prenatal risk factors of adverse birth outcomes. 

Nutrition during Infancy and Risk of Childhood Obesity  

Exclusive breastfeeding for at least four months is associated with a lower prevalence of overweight and obesity in mothers and their children after 2–5 years from delivery 

Comments: Exclusive breastfeeding is the gold standard for infant feeding because it promotes adequate growth and development, excellent nutritional status, and appropriate psychological development. In addition, due to the special composition of breast milk in bioactive and immunogenic substances, it effectively protects against numerous infectious diseases and allergic processes. Breastfeeding has also been suggested as a preventive measure against obesity, which can further reduce long-term negative health outcomes for both women and children [7, 8]. 

The current study evaluated the role of breastfeeding on maternal and childhood overweight and obesity. The data showed that exclusive breastfeeding for at least 4 months was associated with a twofold lower risk for maternal and childhood overweight and obesity after 2–5 years from delivery, independent from maternal age, educational and economic status, and smoking habits. 

The study strengths include the relatively large number of participants. 

The main study limitation is its retrospective cross-sectional design, and therefore, associations but not causation can be derived from the data. 

However, the study confirms the findings of previous studies about the role of exclusive breastfeeding for at least 4 months on protection from postpartum maternal weight gain and against childhood overweight and obesity. 

Effects of a novel infant formula on weight gain, body composition, safety and tolerability to infants: the INNOVA 2020 study 

Comments: Despite efforts to promote breastfeeding, there are many social factors or maternal illness that cause many mothers to stop breastfeeding prematurely. Therefore, there is a need for infant formulas designed with an optimal nutritional composition essential to promote the adequate growth and development. Continuous research has led to the development of infant formula mimicking human milk with the incorporation of various food ingredients to meet the nutritional needs of infants and to contribute to better development. Based on certain studies suggesting that a high protein intake in the early stages of life may be the cause of obesity and increased risk of metabolic disease in later stages of life [9], the protein composition of infant formulas has been adjusted in both quality and quantity, reducing the protein intake and change in the whey/casein ratio. The development of infant formula containing bovine α-lactalbumin (part of the whey proteins) allowed the reduction in the protein content of the formula. Also, the relatively high content of long-chain polyunsaturated fatty acids of both the n-6 and n-3 series, especially arachidonic acid (20:4 n-6) and docosahexaenoic acid (22:6 n-3) in human milk and their proven effects on the cognitive development of infants [10], has led to the incorporation of these fatty acids into infant formulas. 

The current study reports the results of a randomized controlled trial that aimed to evaluate a novel starting infant formula with reduced protein content and lower casein/whey protein ratio (by increasing the content of α-lactalbumin) compared to a standard formula on the safety, tolerability, and efficacy on weight gain and body composition of infants up to 6 and 12 months. Infants were divided into three groups: group 1 received the novel formula (INN, n = 70), with a lower amount of protein, a lower casein/whey protein ratio, a double amount of docosahexaenoic acid/arachidonic acid than the standard formula with the addition of thermally inactivated postbiotic (Bifidobacterium animalis subsp. lactis). Group 2 received the standard formula (STD, n = 70) and the third group was exclusively breastfed and used as a reference (BFD, n = 70). Weight gain was higher in both formula groups than in the BFD group at 6 and 12 months, whereas no differences were found between STD and INN groups either at 6 or at 12 months. Body mass index was higher in infants fed the two formulas compared with the BFD group. Nevertheless, body composition, length, head circumference, and tricipital/subscapular skinfolds were alike between groups. All groups showed similar digestive tolerance and infant behavior. However, a higher frequency of gastrointestinal symptoms was reported in the STD formula group, followed by the INN formula, and the BFD groups. Atopic dermatitis, bronchitis, and bronchiolitis were significantly more prevalent among infants who were fed the STD formula compared to those fed the INN formula or breastfed. 

The strengths of the study are the multicenter, randomized controlled, double-blind clinical trial design and also the anthropometric measurements that were done at every study visit by a professional team. 

The new formula (INN) seems to be a promising one, since it was considered safe and with fewer gastrointestinal symptoms compared with the STD formula, possibly due to the addition of thermally inactivated postbiotic. Also, weight gain and body composition with the consumption of the new formula were within the normal limits, according to WHO standards. 

Different protein intake in the first year and its effects on adiposity rebound and obesity throughout childhood: 11 years follow-up of a randomized controlled trial  

Comments: There is compelling evidence from observational studies and some randomized clinical trials demonstrating that a high protein intake during the first year of life is associ- ated with higher body mass index (BMI), higher fat mass, as well as increased risk of overweight or obesity later in life [11, 12]. 

It is hypothesized that higher protein intake stimulates growth and adipogenesis through the insulin growth factor 1 axis and the mammalian target of rapamycin pathway [13]. The “early protein hypothesis” was tested in a previous randomized clinical trial [14], which showed a lower concentration of insulinogenic amino acids and a lesser insulin growth factor 1 axis activation in breastfed infants and in infants fed with a lower protein content formula (similar to that of human milk) compared with infants fed with a higher protein content formula. 

The current study examined whether protein supply in infancy affects the adiposity rebound, BMI, and overweight and obesity up to 11 years of age. The researchers randomized formula-fed term infants (n = 1,090) within the first 2 months of life to isoenergetic formula with higher or lower protein content within the range stipulated by EU legislation in 2001. A breastfed reference group (n = 588) was included. They found that compared to conventional high protein formula, feeding lower protein formula in infancy lowers BMI trajectories up to 11 years and achieves similar BMI values at adiposity rebound as observed in breastfed infants. Of note, timing of and BMI at adiposity rebound were strongly associated with later obesity. Thus, by using the lower protein formula, it can be possible to avoid excessive fat mass acquisition related to early adiposity rebound, and this may be an important opportunity for targeted effective strategies for promotion of later health. 

The study strengths are the inclusion of a large number of infants from five European countries that makes data more generalizable, the double-blind randomized design of the study, and the long follow-up period up to 11 years. 

This study corroborates previous data about the importance to avoid excessive protein intake in infancy, which may contribute to reduced burden of childhood obesity. 

The effectiveness of interventions during the first 1,000 days to improve energy balance-related behaviors or prevent overweight/obesity in children from socio-economically disadvantaged families of high-income countries: a systematic review 

Comments: The nutrition of infants in the first 1,000 days of life, from conception through 2 years of age, has both immediate and long-term health consequences. These include nutrition-related metabolic, immune, neurocognitive, and epigenetic changes, which program long-term health [15]. The first 1,000 days is also an appropriate time to support parents to promote a healthy lifestyle and prevent obesity for their children. 

This systematic review examined effectiveness of family-based interventions during the first 1,000 days of life in improving energy balance–related behaviors or prevent- ing overweight/obesity in children from families experiencing socioeconomic disadvantage. Interestingly, after a search of five databases on published articles over three decades, only 33 articles were eligible for inclusion in this systematic review. They found 24 distinct interventions which were classified into three types: those specifically aimed at preventing overweight and obesity in children (n = 6); those mostly focused on promoting healthy feeding practices and diet (n = 5); and broad parent support programs aimed at enhancing the general health and bonding of the mother-child dyad (n = 13). The findings showed that there was some evidence of beneficial impact of interventions on obesity risk and associated behaviors (breastfeeding, responsive feeding, diet, sedentary and movement behaviors, and sleep). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, if the intervention continued for at least 2 years postnatally and was multibehavioral. This emphasizes the importance of early education and intervention to promote healthy lifestyle habits. Effective interventions were more likely to target first-time mothers and involve professional delivery agents, multidisciplinary teams, and peer groups. 

Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior only. Cocreation with stakeholders, including parents, and adherence to frameworks were additional elements for more practical, comprehensive, and effective programs. 

The strengths of this systematic review are that most included studies (∼70%) were 

randomized controlled trials. Only studies that reported interventions required to target families experiencing socioeconomic disadvantage were included and interventions were required to be implemented prior to age of 2 years to really evaluate the effectiveness of interventions during the first 1,000 days. 

Moreover, the search strategy of the studies was evaluated according to the PICOT framework: Population (parents experiencing socioeconomic disadvantage), Interven- tion (had to be delivered in the first 1,000 days with the aim of improving one or more of the outcomes), Comparison (intervention studies had to include a control group), Outcome (studies had to address one or more of the following outcomes in children: parental feeding practices, eating behaviors, dietary intake, physical activity and movement measures, sedentary behaviors, sleep, and anthropometric or growth measures), and Timeframe for follow-up (at least one of the eligible outcomes had to be assessed for effectiveness beyond the childbirth). 

The main limitation of this systematic review is the inclusion of studies conducted only in high-income countries with possible impact on the generalizability of the findings. 

Nutrition during Childhood and Risk of Childhood Obesity 

Metabolic profiles of ultra-processed food consumption and their role in obesity risk in British children  

Comments: Childhood obesity is a growing health problem in many populations, hence the urgent need to unravel a large number of underlying mechanisms [16, 17]. Among all the risk factors related to childhood obesity, special attention should be certainly given to ultra-processed foods, which are industrial formulations and ready-to-eat or ready-to-heat foods containing additives, such as flavouring or colouring agents, emulsifiers, and preservatives. These products are typically energy dense and high in added sugars (e.g., fructose, high-fructose corn syrup, invert sugar, maltodextrin, dextrose, and lactose), salt, saturated or trans fatty acids, and other modified oils (hydrogenated or interesterified). Although several studies in adulthood and in childhood have demonstrated that the worldwide shift toward a dramatic increase in the consumption of ultra-processed foods appears partly responsible for the global obesity epidemic and may contribute to an increased risk of cardiometabolic diseases, the underlying mechanisms remain unclear. In this study performed in a large British population–based birth cohort, authors were able to describe a metabolic profile of ultra-processed food consumption in plasma. Particularly, by evaluating the plasma nuclear magnetic resonance metabolic profiles, authors have shown among British children that specific nutrient intake contributes to some of this ultra-processed food-associated metabolic profile. Particularly, higher levels of citrate, glutamine, and monounsaturated fatty acids and lower levels of branched-chain and aromatic amino acids may contribute to the association between a higher-level consumption of ultra-processed foods during childhood and an impaired metabolomic profiles and fat mass accumulation in children. These data clearly illustrated the need of a complete characterization of the metabolic effects of ultra-processed foods, which might affect multiple metabolic traits, many of which contribute to obesity risk in children and adolescents. Therefore, further studies characterizing the metabolic profiles associated with ultra-processed foods are still needed in order to elucidate the mechanisms linking diet, obesity, and disease development, even during childhood. A complete understanding of the molecular pathways underlying weight gain may facilitate in- interventions that prevent their initiation or interrupt their progression prior to clinical disease. 

Effects of foods, beverages and macronutrients on BMI z-score and body composition in children and adolescents: a systematic review and meta-analysis of randomized controlled trials 

Diet is recognized as the essential component for the prevention and treatment of overweight and obesity among children and adolescents worldwide. Many dietary interventions targeting children and adolescents with overweight and obesity are leaning toward the Mediterranean diet [18, 19]. However, several studies have clearly shown that not only diet composition but also several independent factors including dietary patterns and adherence to a healthy dietary pattern might be challenging to children and adolescents with overweight and obesity because they often present with a relatively poor diet quality. Therefore, in this study, authors attempted to perform a comprehensive systematic review and meta-analysis to evaluate the independent effect of foods, beverages, and macronutrient composition on body composition in children and adolescents. Interestingly, authors revealed that consumption of higher dairy diets had a small beneficial effect on general body composition by increasing or preserving lean body mass and reducing body fat. Substitution of sugar-sweetened beverages with noncaloric beverages or flavoured milk had a small beneficial effect on body fat, but not on body mass index Z-score, and the composition of macronutrients had no effect on body mass index Z-score or body fat. Although the results reported in this systematic review and meta-analysis must be interpreted with caution due to the fact that the data are based on few studies and some meta-analysis presented with a high heterogeneity, the analysis shows some relevant information. In fact, reported data show that only studies investigating dairy, sugar-sweetened beverages, and macronutrient composition are available. Therefore, the effect of consuming other foods on body composition in children and adolescents with overweight and obesity has not been previously investigated in a randomized controlled setting emphasizing a gap of knowledge for future research. Given the high need for effective strategies to prevent and treat overweight and obesity in children and adolescents, studies and particularly trials investigating other types of foods need to be further performed to completely guide a scientific consensus on how to prioritize within healthy diets needs in order to prevent and treat overweight and obesity among children and adolescents.   

Low dietary diversity for recommended food groups increases the risk of obesity among children: evidence from a Chinese longitudinal study 

Comments: Childhood obesity poses a global health, policy, and research challenge. In 1975, 32 million children under 5 years of age worldwide had overweight or obesity, growing to 42 million by 2020. Although during the last decade the prevalence of child and adolescent obesity has partially plateaued at high levels in most high-income countries, several reports have shown an increase in many low-income and middle-income countries. In addition, most of these epidemiological reports have been dramatically modified by COVID-19 pandemic. In fact, it has shown a substantial weight gain across all age groups in many countries, reflected by a significant increase in the 3-month change in body mass index standard deviation scores during this period [20], associated with profound alterations in glucose and insulin metabolism in children with obesity and overweight [21]. It is well known that obesity arises when a mix of genetic and epigenetic factors, behavioural risk patterns, and broader environmental and sociocultural influences induce an imbalance of the two body weight regulation systems, namely energy homeostasis and cognitive-emotional control. Although the research has focused on the role of single nutrients in obesity, novel data have pointed out that dietary pattern analysis might represent a novel approach for assessing the association between diet and the risk of chronic diseases, including obesity. Dietary pattern analysis involves investigating the effects of the overall diet rather than individual nutrients or foods, and this approach may thus be more indicative of disease risk than individual foods or nutrients. Therefore, in this study, by evaluating the overall  diet through the dietary diversity score, authors demonstrated that low dietary diversity for recommended food groups is associated with an increased risk of Chinese children being overweight and obese. Although some limitations related to the short period of evaluation and the impossibility to minimize the effects of confounding or confounding factors (such as physical activity, genetic factors, and other) on the analysis, these data add relevant information on diet approach for the prevention and treatment of childhood obesity. Therefore, not only unhealthy foods such as processed foods, refined foods, and sugar-sweetened beverages need to be discouraged but also a dietary diversity for recommended foods should be encouraged to improve dietary quality by ensuring adequate nutrient intake, balanced energy intake, and healthy growth. Therefore, more attention should be paid to the dietary diversification of recommended foods as a preventive measure for childhood obesity, and this should become a dietary habit for children. 

Combined intake of sugar-sweetened beverages and sugar-containing ultra-processed foods is associated with an increase in body mass index during early childhood 

Comments: Sugar is a nutrient of concern mostly added to beverages. A large body of literature have studied the relationship between sugar-sweetened beverages and several non-communicable diseases, including not only obesity in childhood and adulthood but also cancer, diabetes, and cardiovascular diseases. Therefore, the WHO recommends limiting the intake of energy from free sugars (i.e., added sugars plus honey, syrups, and sugars in juiced or pureed fruit and vegetables) to less than 10% to prevent excess body weight and dental caries and to less than 5% for additional health benefits. Of note, sugar-sweetened beverages warrant special attention as there is consistent evidence from multiple study designs on its combined consumption with sugar-containing ultra-processed product, thus potentially and exponentially impacting the known adverse outcomes on weight, bone and joint health, sleep and psychological factors during childhood, and eventual adult diseases. Interestingly, in this study, authors attempted to examine the associations between intake of sugar-sweetened beverages and sugar-containing ultra-processed foods, both combined and individually, and 2-year changes of body mass index Z-scores (BMIZ) among children ages 2–7 years in Uruguay in a longitudinal cohort. Particularly, results showed that the consumption increased the BMIZ when the children had an early and current intake. The consumption of sugar-sweetened beverages and sugar-containing ultra-processed product foods rose between the two waves, and, by the end of the follow-up, 18.9% of children consumed sugar-sweetened beverages and 86.5% consumed sugar-containing ultra-processed product foods. Furthermore, changes in BMIZ between the two waves were higher in children with an intake of two or more sugar-sweetened beverages and sugar-containing ultra-processed product foods in the first wave. Additionally, changes in BMIZ and combined intake of sugar-sweetened beverages plus sugar-containing ultra-processed product foods may indicate that an additive risk in the presence of both sugar-containing products may have occurred. Thus, data further reinforce the importance of effective intervention approaches and public health strategies to prevent the excessive consumption of both sweetened beverages and sugar-containing ultra-processed product foods, in all ages and particularly in early ages. In fact, young children have an innate preference for sweet foods, which may contribute to increased consumption of sugar-containing ultra-processed foods, such as cookies, cakes, sweets, and sugar-sweetened beverages, thus representing a target crucial age in which strategies need to be started. 

Nutrition and Risk of Obesity-Related Comorbidities  

Scientific evidence of the association between oral intake of OMEGA-3 and OMEGA-6 fatty acids and the metabolic syndrome in adolescents: a systematic review 

Comments: Unique definition and particularly therapeutic scheme for metabolic syndrome in children and adolescents are not currently available [22]. Most of these gaps might be related to the fact that more than 40 definitions of metabolic syndrome in children and adolescents have been suggested in the literature; thus its diagnostic criteria have not been standardized yet. However, although uniform guidelines on its definition are still lacking, certainly insulin resistance, central obesity, dyslipidaemia, and hypertension are considered the main components of this syndrome. Although the first recommended approach to all these pathological conditions in children and adolescents is lifestyle intervention (diet and physical exercise), still robust data evaluating the role of several factors in the risk of developing metabolic syndrome are lacking. Among the diet-related risk factors, certainly the effects of some peculiar classes of fatty acids (namely omega-3 and omega-6) might have a relevant role due to their relevant effects on human health [23]. Fatty acids can be classified into three categories based on the number of double bonds present in side chains: saturated fatty acids (no double bonds), monounsaturated fatty acids (a single double bond), and polyunsaturated fatty acids (PUFA, more than 2 double bonds). Moreover, fatty acids can be classified by their carbon chain length and the position of the first double bond on methyl terminal (omega or n-fatty acids). PUFA, mainly categorized into omega-3 and omega-6 fatty acids, play key roles in regulating body homeostasis and cannot be produced endogenously. The biological properties of PUFA are still the focus of considerable attention as they are thought to play an important role in several conditions, such as cardiovascular diseases, cancer, depression, insulin resistance, lipid metabolism, and nonalcoholic fatty liver disease. Although, in adults, insufficient intake of omega-3 fatty acids has been associated with the risk of developing metabolic syndrome, but no significant results were found with omega-6 fatty acids, few data are still available in children and adolescents. Therefore, in this interesting systematic review of the literature on the scientific evidence, authors were able to summarize the main data available in childhood. Particularly, authors revealed that to date, scientific evidence is controversial on the association between omega-3 fatty acid oral intake and the metabolic syndrome in adolescents, due to the heterogeneity among studies and the divergence of results for the same components adopted in the definition of the syndrome. Results also showed that the effect of omega-3 fatty acids appears to be different between genders. Therefore, results of this analysis clearly show that longitudinal studies with omega-3 and omega-6 fatty acids are recommended to assist in understanding the association/effects with the metabolic syndrome. Thus, although the prevention and/or treatment of metabolic syndrome are complex pro- cesses, the nutritional interventions need to receive considerable attention, with be- ing diet certainly a key component. The complete characterization of all the dietetic factors related to metabolic risk might properly guide the approach to children and adolescents with metabolic syndrome with the aim to prevent all the metabolic and cardiovascular complications. 

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