Dietary Patterns Exhibit Sex-Specific Associations with Adiposity and Metabolic Risk in a Cross-Sectional Study in Urban Mexican Adolescents

Breastfeeding Duration and Cardiometabolic Health during Adolescence: A Longitudinal Analysis

OBJECTIVE

To investigate the longitudinal association between breastfeeding duration and cardiometabolic health, using repeated measures study design among children and adolescents.

STUDY DESIGN

This study included 634 offsprings aged 10 to 21 years (52% female) from the Early Life Exposure in Mexico to Environmental Toxicants birth cohort followed up to four time points during adolescence. Breastfeeding duration was prospectively quantified using questionnaires during early childhood. Cardiometabolic risk factors, body composition, and weight-related biomarkers were assessed as outcomes during adolescent follow-up visits. Sex-stratified linear mixed-effects models were used to model the association between quartiles of breastfeeding duration and outcomes, adjusting for age and additional covariates.

RESULTS

Median breastfeeding duration was 7 months (minimum = 0, maximum = 36). Boys in the second quartile (median breastfeeding = 5 months) had lower total fat mass % (β (SE) -3.2 (1.5) P = .037), and higher lean mass % (3.1 (1.6) P = .049) and skeletal muscle mass % (1.8 (0.8) P = .031) compared with the reference group (median breastfeeding = 2 months). A positive linear trend between breastfeeding duration and trunk lean mass % (0.1 (0.04) P = .035) was found among girls. No association was found with other cardiometabolic indicators.

CONCLUSION

Despite sex-specific associations of breastfeeding duration with body composition, there was a lack of substantial evidence for the protective effects of breastfeeding against impaired cardiometabolic health during adolescence among Mexican youth. Further longitudinal studies with a robust assessment of breastfeeding are recommended.

Prenatal dietary patterns in relation to adolescent offspring adiposity and adipokines in a Mexico City cohort

Maternal diet during pregnancy has been associated with obesity among offspring. The extent to which trimester-specific dietary patterns are associated with markers of adiposity during adolescence remains unclear. We examined associations between prenatal diet patterns with adolescent offspring measures of adiposity and adipokines in 384 mother-adolescent dyads from the Mexico City ELEMENT cohort. Trimester-specific diet patterns were derived from principal component analysis of food frequency questionnaire data. Adolescent anthropometry and serum leptin and adiponectin were measured at 10-17 years. Three maternal diet patterns were identified: Prudent Diet (PD), high in fish and vegetables, the High Meat and Fat Diet (HMFD), high in pork and processed meats, and the Transitioning Mexican Diet (TMD), high in corn tortillas and sugar-sweetened beverages. Multiple linear regression was used to estimate sex-stratified associations among quartiles of diet patterns with adiposity and adipokines, adjusting for maternal marital status, education, and parity. First trimester TMD was associated with greater anthropometric measures and higher leptin in females, while third trimester HMFD was associated higher body fat percentage, triceps thickness, waist circumference, and leptin, but lower adiponectin among males. Contrary to expectation, there were positive associations between the trimester 1 PD pattern and anthropometric measurements in females, and for trimester 2 HMFD and TMD patterns with adipokines among males. Findings suggest maternal diet patterns may influence offspring adiposity markers during adolescence in a sex-specific manner.

Sleep duration and timing are prospectively linked with insulin resistance during late adolescence

OBJECTIVE

The aim of this study was to evaluate whether short sleep duration or later sleep timing is a risk factor for insulin resistance (IR) in late adolescence.

METHODS

Mexico City adolescents enrolled in a longitudinal birth cohort (ELEMENT) took part in two study visits during peri-puberty that occurred approximately 2 years apart. IR was assessed with serum glucose and insulin. Four groups were defined using puberty-specific cut points: no IR over the follow-up period, transition from normal to IR, transition from IR to normal, and IR at both time points. Baseline sleep assessments were measured with 7-day wrist actigraphy. Multinomial logistic regression models were used to evaluate associations between sleep duration and timing with homeostatic model assessment of insulin resistance categories, adjusting for age, sex, and baseline pubertal status.

RESULTS

Adolescents who were ≥ 1 hour below the sleep duration recommendations-for-age were 2.74 times more likely to develop IR (95% CI: 1.0-7.4). Similarly, adolescents who were in the latest category of sleep midpoint (>4:33 a.m.) were more likely than those with earliest midpoints (1 a.m.-3 a.m.) to develop IR (odds ratio = 2.63, 95% CI: 1.0-6.7). Changes in adiposity over follow-up did not mediate sleep and IR.

CONCLUSIONS

Insufficient sleep duration and late sleep timing were associated with development of IR over a 2-year period in late adolescence.

DNA Methylation Is a Potential Biomarker for Cardiometabolic Health in Mexican Children and Adolescents

DNA methylation (DNAm) is a plausible mechanism underlying cardiometabolic abnormalities, but evidence is limited among youth. This analysis included 410 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to two time points in late childhood/adolescence. At Time 1, DNAm was quantified in blood leukocytes at long interspersed nuclear elements (LINE-1), H19, and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2), and at Time 2 in peroxisome proliferator-activated receptor alpha (PPAR-α). At each time point, cardiometabolic risk factors were assessed including lipid profiles, glucose, blood pressure, and anthropometry. Linear mixed effects models were used for LINE-1, H19, and 11β-HSD-2 to account for the repeated-measure outcomes. Linear regression models were conducted for the cross-sectional association between PPAR-α with the outcomes. DNAm at LINE-1 was associated with log glucose at site 1 [β = -0.029, p = 0.0006] and with log high-density lipoprotein cholesterol at site 3 [β = 0.063, p = 0.0072]. 11β-HSD-2 DNAm at site 4 was associated with log glucose (β = -0.018, p = 0.0018). DNAm at LINE-1 and 11β-HSD-2 was associated with few cardiometabolic risk factors among youth in a locus-specific manner. These findings underscore the potential for epigenetic biomarkers to increase our understanding of cardiometabolic risk earlier in life.

Sedentary patterns and cardiometabolic risk factors in Mexican children and adolescents: analysis of longitudinal data

BACKGROUND

Sedentary behavior is a modifiable risk factor for cardiometabolic health; however, the assessment of total sedentary time may not capture youth's highly active and interrupted activity patterns. This study examined the associations between sedentary activity patterns and cardiometabolic risk factors among Mexican youth, who have a disproportionate burden of metabolic diseases, using a repeated measure design out of a longitudinal data.

METHODS

570 subjects in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) birth cohort, who were followed up to three-time points during adolescence, were included. Bout duration, and frequency and percentages of waking time spent in specific intensities of activity, were quantified using ActiGraph wGT3X-BT wrist accelerometers. Self-reported questionnaires were used to query the usual duration of different sedentary behaviors. Outcomes were fasting lipid profile, markers for glucose homeostasis, anthropometry, and blood pressure. Associations were modeled using linear mixed-effects models, and isotemporal substitution approach was additionally used to assess the effect of replacing objectively assessed sedentary activity with other activity intensities, adjusting for potential confounders.

RESULTS

Each hour of self-reported screen-based time was positively associated with diastolic blood pressure (mm Hg) [β = 0.30, 95% confidence interval (95% CI) = 0.10, 0.51], and an hour of other sedentary time was associated with log serum glucose (mg/dL) [β = 0.01, 95% CI = 0.004, 0.017]. Substitution models showed that replacing 5% of sedentary time with moderate to vigorous physical activity (MVPA) was associated with lower waist circumference (cm) [β = - 1.35, 95% CI = - 1.91, - 0.79] and log serum triglycerides (mg/dL) [β = - 0.11, 95% CI = - 0.18, - 0.03]. Substituting one uninterrupted sedentary bout with light activity was associated with lower insulin (μIU/mL) [β = - 0.06, 95% CI = - 0.10, - 0.02].

CONCLUSIONS

Sedentary time was associated with cardiometabolic risk factors in Mexican youth in a context-specific manner. Replacing sedentary time with higher intensities was associated with improvements in some cardiometabolic markers.

The Role of Dietary Patterns and Dietary Quality on Body Composition of Adolescents in Chinese College

There is limited evidence regarding the effects of dietary pattern and dietary quality on the risk of unhealthy weight status and related body composition in Chinese adolescence. In particular, studies using bioelectrical impedance analyzer (BIA) in these subjects are rare. The aim of this study was to evaluate the role of diet in body composition, to find a healthy dietary pattern for Chinese youth, and to promote the application of BIA among this population. A total of 498 participants aged from 18 to 22 years old were included. Dietary patterns were identified by principal components analysis. Energy-adjusted dietary inflammatory index (DII) and diet balance index (DBI) were calculated based on semi-quantitative food frequency questionnaire. Multivariate linear regression and logistic regression analysis were used to examine the relationship of dietary patterns, dietary quality with body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and the effect of dietary factors on BMI levels. The majority of participants with overweight and obesity had abdominal obesity, and there was 3.7% abdominal obesity in normal BMI individuals. Four dietary patterns were detected in the subjects. The pattern with the higher energy intake, which was close to the Western diet, was positively correlated with BMI (β = 0.326, p = 0.018) and FMI (β = 0.201, p = 0.043), while being negatively correlated with FFMI (β = −0.183, p = 0.021). Individuals who followed the pattern similar to the Mediterranean diet had a higher basal metabolic rate (BMR), and the highest fat free mass, soft lean mass, and skeletal muscle mass (p < 0.05) but the lowest FMI, visceral fat area (VFA), waist−hip ratio, and FMI/FFMI ratio (p < 0.05). Higher energy-adjusted DII was associated with high BMI. Higher bound score (HBS) (β = −0.018, p = 0.010) and diet quality distance (DQD) (β = −0.012, p = 0.015) were both negatively correlated with FFMI. In conclusion, fat or muscle indexes, such as BMR, FMI, and FFMI, had an important role in predicting overweight and obesity, which suggested the importance of applying BIA among Chinese college students. Students who followed healthful dietary patterns or the high-quality diet that is similar to the Mediterranean diet but not close to the Western diet were more likely to have a healthy BMI and normal body composition.

Maternal carbohydrate intake during pregnancy is associated with child peripubertal markers of metabolic health but not adiposity

OBJECTIVE

To examine the associations of trimester-specific maternal prenatal carbohydrate (CHO) intake with offspring adiposity and metabolic health during peripuberty.

DESIGN

Prospective cohort study in which maternal dietary intake was collected via validated FFQ during each trimester. Offspring adiposity and metabolic biomarkers were evaluated at age 8-14 years. We used multivariable linear regression to examine associations between total energy-adjusted maternal CHO intake and offspring BMI z-score, skinfold thickness and metabolic syndrome risk z-score calculated as the average of waist circumference, fasting glucose, fasting C-peptide, TAG:HDL and systolic blood pressure + diastolic blood pressure/2.

SETTING

Mexico City, Mexico.

PARTICIPANTS

237 mother-child pairs in the Early Life Exposure in Mexico to Environmental Toxicants cohort.

RESULTS

We found non-linear associations of maternal CHO intake during pregnancy with offspring metabolic health during peripuberty. After adjusting for maternal age, and child age, sex and pubertal status, children whose mothers were in the fourth v. first quartile of total CHO intake during the third trimester had 0·42 (95 % CI -0·01, 0·08) ng/ml lower C-peptide and 0·10 (95 % CI -0·02, 0·22) units lower C-peptide insulin resistance (CP-IR). We found similar magnitude and direction of association with respect to net CHO intake during the first trimester and offspring C-peptide and CP-IR. Maternal CHO intake during pregnancy was not associated with offspring adiposity.

CONCLUSIONS

In this study of mother-child pairs in Mexico City, children born to women in the highest quartile of CHO intake during pregnancy had lowest C-peptide and CP-IR during peripuberty. Additional research is warranted to replicate and identify mechanisms.

Prevalence of metabolic syndrome among the adult population in western China and the association with socioeconomic and individual factors: four cross-sectional studies

OBJECTIVES

This study explored the prevalence of and individual influencing factors for metabolic syndrome (MS) as well as associated socioeconomic factors and regional aggregation.

DESIGN

Four cross-sectional surveys were analysed for trends in MS and associations with socioeconomic and individual factors through multilevel logistic regression analyses. The risk associated with nutrient intake was also assessed through a dietary survey in 2015.

SETTING

From 2010 to 2018, 8-15 counties/districts of West China were included.

PARTICIPANTS

A total of 28 274 adults were included in the prevalence analysis. A total of 23 708 adults were used to analyse the related factors.

RESULTS

The overall prevalence of MS ranged from 21.4% to 27.8% over the 8 years, remaining basically stable within the 95% CI. Our study found that the urbanisation rate and hospital beds per 1000 people were positively associated with MS, and the number of doctors in healthcare institutions per 1000 persons was negatively associated with MS. The ORs for females, people with college education and higher and unmarried or single people were 1.49, 0.67 and 0.51, respectively (p<0.05). The ORs of people who smoked at least 20 cigarettes/day, ate more than 100 g of red meat/day, consumed fruit or vegetable juice and drank carbonated soft drinks less than weekly were 1.10, 1.16, 1.19-1.27 and 0.81-0.84, respectively. The ORs rose with increasing sedentary time and decreased with higher physical activity.

CONCLUSION

The high burden of MS, unreasonable proportions of energy and micronutrient intake and low percentage of high levels of physical activity were the major challenges to public health in western China. Improving the human resources component of medical services, such as the number of doctors, increasing the availability of public sports facilities and E-health tools and improving individual dietary quality and education might help prevent MS.

Diet Quality Scores and Cardiometabolic Risk Factors in Mexican Children and Adolescents: A Longitudinal Analysis

There is limited evidence for the effects of diet on cardiometabolic profiles during the pubertal transition. We collected repeated measures of diet quality and cardiometabolic risk factors among Mexican youth. This analysis included 574 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to three time points. Dietary Approaches to Stop Hypertension (DASH), alternate Mediterranean Diet (aMedDiet), and Children’s Dietary Inflammatory Index (C-DIITM) scores were computed from food frequency questionnaires. Higher DASH and aMedDiet scores reflect a higher diet quality, and lower C-DII scores reflect an anti-inflammatory diet. Cardiometabolic risk factors were lipid profile, glucose homeostasis, blood pressure, and waist circumference. Linear mixed models were used between quartiles of each diet score and outcomes. Compared to the first quartile, the fourth DASH quartile was inversely associated with log serum insulin (μIU/mL) [β = −0.19, p = 0.0034] and log-Homeostatic Model Assessment of Insulin Resistance [β = −0.25, p = 0.0008]. Additionally, log serum triglycerides (mg/dL) was linearly associated with aMedDiet score [β = −0.03, p = 0.0022]. Boys in the highest aMedDiet quartile had higher serum high-density lipoprotein cholesterol (mg/dL) [β = 4.13, p = 0.0034] compared to the reference quartile. Higher diet quality was associated with a better cardiometabolic profile among Mexican youth.

Urinary metabolic biomarkers of diet quality in European children are associated with metabolic health

Urinary metabolic profiling is a promising powerful tool to reflect dietary intake and can help understand metabolic alterations in response to diet quality. Here, we used 1H NMR spectroscopy in a multicountry study in European children (1147 children from 6 different cohorts) and identified a common panel of 4 urinary metabolites (hippurate, N-methylnicotinic acid, urea, and sucrose) that was predictive of Mediterranean diet adherence (KIDMED) and ultra-processed food consumption and also had higher capacity in discriminating children's diet quality than that of established sociodemographic determinants. Further, we showed that the identified metabolite panel also reflected the associations of these diet quality indicators with C-peptide, a stable and accurate marker of insulin resistance and future risk of metabolic disease. This methodology enables objective assessment of dietary patterns in European child populations, complementary to traditional questionary methods, and can be used in future studies to evaluate diet quality. Moreover, this knowledge can provide mechanistic evidence of common biological pathways that characterize healthy and unhealthy dietary patterns, and diet-related molecular alterations that could associate to metabolic disease.

Dietary patterns among adolescents and associated factors: longitudinal study on sedentary behavior, physical activity, diet and adolescent health

The aim of the present study was to identify dietary patterns and associations with socioeconomic characteristics, lifestyle, nutritional status, lipid profile and inflammatory profile in adolescents. A cross-sectional study was conducted with a probabilistic sample using baseline data (2014) from the Longitudinal Study on Sedentary Behavior, Physical Activity, Eating Habits and Adolescent Health. A total of 1,438 adolescents (10 to 14 years old) from public schools in the city of João Pessoa, Brazil, participated in the study. Data were collected on socioeconomic characteristics, nutritional status, lifestyle and the results of biochemical tests. Dietary data were obtained using the 24-hour recall method and dietary patterns were identified by exploratory factor analysis. Associations of interest were estimated using multiple logistic regression. Three dietary patterns were found: "Traditional", "Snacks" and "Western". These patterns were associated with age, socioeconomic status, parental education and lifestyle. The "Traditional" pattern was associated lower adiposity and a better lipid profile. However, with the increase in age, greater frequencies of the "Snacks" and "Western" patterns were found. The present findings underscore the need for strategies that encourage healthy behaviors.

Association between Eating Patterns and Excess Body Weight in Adolescents

Background: Excess body weight is a risk factor for the development of diseases. Adolescence is a nutritionally vulnerable age group that suffers due to influences on food intake. We aimed to identify the main dietary patterns of adolescents to investigate their association with excess body weight. Methods: This was a cross-sectional study. Anthropometric measurements (weight and height) were collected to calculate the BMI. Nutritional statuses were classified according to World Health Organization classification. Food consumption data were obtained through a 24-hour recall and food patterns were identified through factor analyses of the main components. The patterns were categorized into quintiles and dichotomized into greater (fourth and fifth quintile) and lower (first to third quintile) adherences. Binomial regression was used to assess the association between food patterns and excess body weight. The study was conducted in a capital city in Northeast Brazil from adolescents aged between 10 and 19 years in 826 public schools. Results: Three main food patterns were identified in women and men: coffee with bread (white bread, coffee, fat, and eggs), common Brazilian (white rice, beans, meat, pasta, with negative factor load for regional foods), and mixed pattern (sweets, fruits, biscuits and cakes, vegetables, and dairy products). Adolescents with a greater adherence to the coffee and bread pattern [odds ratio (OR) = 0.68; 95% confidence interval (95% CI): 0.50-0.93] and the common Brazilian pattern (OR = 0.72; 95% CI: 0.53-0.99) had a lower chance of being excess body weight than those with lower adherence. Conclusions: Three main eating patterns were identified among adolescents, and greater adherence to the coffee with bread and common Brazilian patterns implied a lower chance of excess body weight.

Association between postpartum low-carbohydrate-diet scores and glucose levels in Chinese women

OBJECTIVES

Views on the relationship between a low-carbohydrate diet (LCD) and glucose levels are controversial, and no study, to our knowledge, has examined this association in postpartum women. We aimed to explore the association between postpartum LCD scores and glucose levels.

METHODS

We included 500 postpartum women from a prospective cohort study in Guangzhou, China, during 2017 and 2018. Dietary information during the first month after delivery was assessed via a validated food frequency questionnaire. The overall, animal, and plant LCD scores were determined based on percentages of energy from carbohydrate, protein, and fat. Higher scores reflected higher intakes of fat and protein and lower intakes of carbohydrate. At 6 to 8 wk postpartum, women with previous gestational diabetes mellitus underwent oral glucose tolerance tests (n = 104), and the others had fasting plasma glucose (FPG) tests (n = 396). Multivariable linear, quantile, and logistic regressions were conducted.

RESULTS

Of the 500 participants, 71 (14.20%) developed impaired fasting glucose. Animal LCD score was positively associated with FPG levels (β = 0.007, P = 0.017), but quantile regression showed that LCD scores were related to FPG only in women with lower FPG levels; they had no significant association in those with higher FPG levels. No significant interaction effect on FPG was found between LCD scores and history of gestational diabetes mellitus (P_interaction > 0.40). Furthermore, the relationships between the three LCD scores and risk of developing impaired fasting glucose were not statistically significant.

CONCLUSIONS

Animal LCD score during puerperium may be positively associated with FPG levels in the early postpartum period in Chinese women, but no interactions with history of gestational diabetes mellitus were observed. Stronger associations were observed in women with lower FPG levels.

Greater cumulative exposure to a pro-inflammatory diet is associated with higher metabolic syndrome score and blood pressure in young Mexican adults

Low-grade inflammation is a suggested mechanism in the development of metabolic syndrome (MetS), and diet could act as a regulator. Therefore, we hypothesized that the cumulative Dietary Inflammatory Index (DII®) exposure from diet during infancy through adulthood would be positively associated with the MetS and its components in young Mexican adults. One hundred participants from the Early Life Exposures in Mexico to Environmental Toxicants cohort were included in this analysis. The dietary inflammatory potential of the diet (without supplements) was assessed using 27 nutrients obtained from repeated food frequency questionnaires (1-22 years) using the DII, a validated score. The cumulative exposure of DII was constructed using the area under the curve (AUC of DII). The MetS was defined using the International Diabetes Federation criteria, and the Metabolic Syndrome Risk Z-score (MetRisk Z-score) was estimated. Linear regressions were conducted to assess the association between the AUC of DII with MetRisk Z-score and MetS components, adjusting for sex, socioeconomic status, smoking status, physical activity, birth weight, and body mass index. In adulthood, the mean age was 21.5 years, 54% were male, and 17% had MetS. Positive associations were found between AUC of DII with MetRisk Z-score (β = .12; 95% confidence interval [CI]: 0.03-0.22; P = .009) and systolic (β = .33; 95% CI: 0.05-0.61; P = .023) and diastolic blood pressure (β = .24; 95% CI: 0.01-0.47; P = .040). A cumulative proinflammatory diet from infancy through young adulthood is associated with higher MetRisk Z-scores as well as blood pressure. These findings may provide evidence for the implementation of anti-inflammatory diet interventions throughout early life for the prevention of cardiometabolic risk.

Obesogenic Lifestyle and Its Influence on Adiposity in Children and Adolescents, Evidence from Mexico

Overweight (OW) and obesity (OB) during childhood/adolescence are major public health problems in Mexico. Several obesogenic lifestyle (OL) risk factors have been identified, but the burden and consequences of them in Mexican children/adolescents remain unclear. The objective of this study was to estimate the prevalence of OL components and describe their relationships with adiposity, and OW/OB. A population-based cross-sectional study of Mexican children/adolescents with nutritional assessment, data collection on daily habits and adiposity as fat-mass index (FMI) by dual-energy X-ray absorptiometry was performed. Individual OL-components: “inactivity,” “excessive screen time,” “insufficient sleep,” “unhealthy-diet”, were defined according to non-adherence to previously published healthy recommendations. Results: 1449 subjects were assessed between March 2015 to April 2018. Sixteen percent of subjects had all four OL-components, 40% had three, 35% had two, 9% had one, and 0.5% had none. A cumulative OL score showed a significant dose–response effect with FMI. The combination of inactivity, excessive screen time, and insufficient sleep showed the highest risk association to OW/OB and higher values of FMI. Conclusions: The prevalence of OL-components was extremely high and associated with increased adiposity and OW/OB. Several interventions are needed to revert this major public health threat.

Dietary Patterns and Childhood Obesity Risk: A Systematic Review

Background: Childhood overweight and obesity are recognized as predictors of the risk of obesity in adulthood. The aim of this systematic literature review was to determine the association between dietary pattern and obesity risk among children. Methods: Articles were selected from databases (Cochrane Library, Lilacs, Eric, Livivo, and PubMed/Medline), without limitations regarding language or date. Database-specific search terms included the key words "obesity," "diet," "dietary pattern," "childhood," "children," "adolescents," and relevant synonyms. The review included studies that reported the assessment of the dietary pattern in childhood and that correlated eating patterns with the obesity risk through cluster analysis (CA) and/or factor analysis and/or principal component analysis and presented odds ratios (ORs). The methodology of the selected studies was evaluated using the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies. Owing to the heterogeneity among the assessments of the association of dietary patterns and obesity, the results are described narratively. Results: Using a selection process in two phases, 16 articles were included. Fifteen studies used a cross-sectional design, and one case-control study. The included studies showed variation in sample size (range = 232 to 10,187 children/adolescents) and age (range = 1-19 years old). The studies reported between two and five dietary patterns each. The OR for the relationship between the dietary pattern and the risk of childhood obesity ranged from OR = 1.02; confidence interval (95% CI) (0.91-1.15) to OR = 3.55; 95% CI (1.80-7.03). In this study, the dietary patterns identified by the studies were given different names. The food intake patterns identified could, in most factor or CA studies, be categorized as (1) potentially obesogenic foods that increased risk of becoming overweight (including fatty cheeses, sugary drinks, processed foods, fast food, candies, snacks, cakes, animal products, whole milk, and refined grains) or (2) food classified as healthy with the weakest association with the risk of becoming overweight or obese (including low levels of sugar and fat and high levels of fruits, vegetables, whole grains, fish, nuts, legumes, and yogurt). Conclusion: Overall, the results indicated from most studies that a diet with a lower percentage of obesogenic foods should be effective in reducing the risk of developing obesity.

Exploring dietary patterns in a Mexican adolescent population: A mixed methods approach

To explore dietary patterns within the context of the nutrition transition among Mexican adolescents, we employed a mixed-methodology that included survey data from a cohort of 550 adolescents and direct ethnographic observations of six families. From the cohort study, we found that diet tended to cluster into 3 patterns. Interpreting the patterns using the ethnographic observations showed that the dietary clustering likely reflected differences in meal organization driven by socioeconomic status (SES). In particular, families of higher SES could afford to prepare larger home-cooked meals on a regular basis while lower SES households had less-stable patterns and greater reliance on processed food. These findings provide a more nuanced interpretation of dietary patterns observed in the Mexico population than is afforded by the food items alone (i.e. a "healthy" or "prudent" pattern versus "unhealthy" or "Westernized").

Dietary Patterns and the Double Burden of Malnutrition in Mexican Adolescents: Results from ENSANUT-2006

Mexico is facing the double burden of malnutrition, and adolescents are not an exception. Diet plays an important role, both in causing overweight and undernutrition. This study aimed to describe the dietary patterns (DPs) of Mexican adolescents and to examine its association with nutritional status using data from adolescents aged 12-19 years (n = 7380) from the National Survey of Health and Nutrition (ENSANUT-2006). Principal component analysis was used to derivate the DPs. Associations between DP and nutritional status were determined by prevalence ratio (PR). Four DPs were identified: nontraditional and breakfast-type, Western, plant-based, and protein-rich. The prevalence of overweight and obesity was higher in adolescents who scored high on the Western pattern (PR: 1.15, 95% CI: 1.08-1.21) or on the plant-based pattern (PR: 1.09, 95% CI: 1.03-1.17). The Western pattern was positively associated with anemia in girls (PR: 1.18, 95% CI: 1.03-1.35), while the nontraditional and breakfast-type pattern was inversely associated with anemia in adolescents aged 12-15 years (PR: 0.87, 95% CI: 0.76-0.99) and in girls (PR: 0.84, 95% CI: 0.75-0.97). The Western and plant-based patterns were simultaneously associated with overweight-obesity and at least one indicator of undernutrition. In the context of the double burden of malnutrition, dietary advice must consider malnutrition in all its forms.

Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) Project

PURPOSE

The Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) Project is a mother-child pregnancy and birth cohort originally initiated in the mid-1990s to explore: (1) whether enhanced mobilisation of lead from maternal bone stores during pregnancy poses a risk to fetal and subsequent offspring neurodevelopment; and (2) whether maternal calcium supplementation during pregnancy and lactation can suppress bone lead mobilisation and mitigate the adverse effects of lead exposure on offspring health and development. Through utilisation of carefully archived biospecimens to measure other prenatal exposures, banking of DNA and rigorous measurement of a diverse array of outcomes, ELEMENT has since evolved into a major resource for research on early life exposures and developmental outcomes.

PARTICIPANTS

n=1643 mother-child pairs sequentially recruited (between 1994 and 2003) during pregnancy or at delivery from maternity hospitals in Mexico City, Mexico.

FINDINGS TO DATE

Maternal bone (eg, patella, tibia) is an endogenous source for fetal lead exposure due to mobilisation of stored lead into circulation during pregnancy and lactation, leading to increased risk of miscarriage, low birth weight and smaller head circumference, and transfer of lead into breastmilk. Daily supplementation with 1200 mg of elemental calcium during pregnancy and lactation reduces lead resorption from maternal bone and thereby, levels of circulating lead. Beyond perinatal outcomes, early life exposure to lead is associated with neurocognitive deficits, behavioural disorders, higher blood pressure and lower weight in offspring during childhood. Some of these relationships were modified by dietary factors; genetic polymorphisms specific for iron, folate and lipid metabolism; and timing of exposure. Research has also expanded to include findings published on other toxicants such as those associated with personal care products and plastics (eg, phthalates, bisphenol A), other metals (eg, mercury, manganese, cadmium), pesticides (organophosphates) and fluoride; other biomarkers (eg, toxicant levels in plasma, hair and teeth); other outcomes (eg, sexual maturation, metabolic syndrome, dental caries); and identification of novel mechanisms via epigenetic and metabolomics profiling.

FUTURE PLANS

As the ELEMENT mothers and children age, we plan to (1) continue studying the long-term consequences of toxicant exposure during the perinatal period on adolescent and young adult outcomes as well as outcomes related to the original ELEMENT mothers, such as their metabolic and bone health during perimenopause; and (2) follow the third generation of participants (children of the children) to study intergenerational effects of in utero exposures.

TRIAL REGISTRATION NUMBER

NCT00558623.

Puberty is a critical window for the impact of diet on mammary gland development in the rabbit

Background

Nutritional changes can affect future lactation efficiency. In a rabbit model, an obesogenic diet initiated before puberty and pursued throughout pregnancy enhances mammary differentiation, but when started during the neonatal period can cause abnormal mammary development in early pregnancy. The aim of this study was to investigate the impact of an unbalanced diet administered during the pubertal period only.

Results

Consuming an obesogenic diet at puberty did not affect either metabolic parameters or certain maternal reproductive parameters at the onset of adulthood. In contrast, at Day 8 of pregnancy, epithelial tissue showed a lower proliferation rate in obesogenic‐diet fed rabbits than in control‐diet fed rabbits. Wap and Cx26 genes, mammary epithelial cell differentiation markers, were upregulated although Wap protein level remained unchanged. However, the expression of genes involved in lipid metabolism and in alveolar formation was not modified.

Conclusion

Taken together, our results demonstrate that the consumption for 5 weeks of an obesogenic diet during the pubertal period initiates mammary structure modifications and affects mammary epithelial cell proliferation and differentiation. Our findings highlight the potentially important role played by unbalanced nutrition during critical early‐life windows in terms of regulating mammary epithelial cell differentiation and subsequent function in adulthood.

Our results demonstrate that the consumption for five weeks of an obesogenic diet during the pubertal period initiates mammary structure modifications and affects mammary epithelial cell proliferation and differentiation. Our findings highlight the potentially important role played by unbalanced nutrition during critical early‐life windows in terms of regulating mammary epithelial cell differentiation and subsequent function in adulthood.

Urate and Nonanoate Mark the Relationship between Sugar-Sweetened Beverage Intake and Blood Pressure in Adolescent Girls: A Metabolomics Analysis in the ELEMENT Cohort

We sought to identify metabolites that mark the relationship of sugar-sweetened beverage (SSB) intake with adiposity and metabolic risk among boys (n = 114) and girls (n = 128) aged 8–14 years. We conducted the analysis in three steps: (1) linear regression to examine associations of SSB intake (quartiles) with adiposity, glycemia, lipids, and blood pressure (BP); (2) least absolute shrinkage and selection operator (LASSO) regression to identify SSB-associated metabolites from an untargeted dataset of 938 metabolites; and (3) linear regression to determine whether SSB-related metabolites are also associated with adiposity and metabolic risk. In girls, SSB intake was associated with marginally higher BP (Q2 vs, Q1: 1.11 [−3.90, 6.13], Q3 vs. Q1: 1.16 [−3.81, 6.13], Q4 vs. Q1: 4.65 [−0.22, 9.53] mmHg systolic blood pressure (SBP); P-trend = 0.07). In boys, SSB intake corresponded with higher C-peptide insulin resistance (Q2 vs. Q1: 0.06 [−0.06, 0.19], Q3 vs. Q1: 0.01 [−0.12, 0.14], Q4 vs. Q1: 0.17 [0.04, 0.30] ng/mL; P-trend = 0.03) and leptin (P-trend = 0.02). LASSO identified 6 annotated metabolites in girls (5-methyl-tetrohydrofolate, phenylephrine, urate, nonanoate, deoxyuridine, sn-glycero-3-phosphocholine) and 3 annotated metabolites in boys (2-piperidinone, octanoylcarnitine, catechol) associated with SSB intake. Among girls, urate and nonanoate marked the relationship of SSB intake with BP. None of the SSB-associated metabolites were related to health outcomes in boys.

Associations between Sleep and Dietary Patterns among Low-Income Children Attending Preschool

BACKGROUND

Sleep disturbances and low-quality diets are prevalent among children in low-income settings, yet the nature of their relationship remains unclear. In particular, whether aspects other than sleep duration, including timing and quality, are associated with dietary patterns has rarely been examined, especially among preschool-aged children.

OBJECTIVE

To evaluate whether nightly and total sleep duration, sleep timing, differences in timing and duration from weekdays to weekends, and sleep quality were related to dietary patterns.

DESIGN

A cross-sectional analysis of children attending preschool. Parents completed questionnaires about children's sleep habits as well as a semiquantitative food frequency questionnaire.

PARTICIPANTS/SETTING

Three hundred fifty-four English-speaking children (49.9% boys) with no serious medical conditions aged 3 to 5 years who were enrolled in Head Start in Michigan (2009-2011) with complete information on sleep and diet.

MAIN OUTCOME MEASURES

Dietary pattern scores derived from food frequency questionnaire.

STATISTICAL ANALYSES PERFORMED

Principal component analysis was used to identify dietary patterns. Separate linear regression models with dietary pattern scores as the dependent variable and continuous sleep measures as independent variables were used to evaluate associations between sleep and diet, adjusting for sex, age, parent education level, and sleep hygiene.

RESULTS

Three dietary patterns were identified: Vegetables, Healthy Proteins, and Sides; Breads and Spreads; and Processed and Fried. Longer average weekend sleep duration and a greater difference in weekend-to-weekday sleep duration was related to lower Vegetables, Healthy Proteins, and Sides pattern scores. Later sleep midpoint during weekdays was related to lower Vegetables, Healthy Proteins, and Sides pattern scores, whereas later sleep midpoint on the weekend was associated with higher Processed and Fried pattern scores. Similarly, a larger weekend-weekday midpoint difference was associated with higher Processed and Fried pattern scores.

CONCLUSIONS

Later sleep timing and differences in sleep duration and timing from weekends to weekdays were related to less-optimal dietary pattern scores in young children.

Metabolomic profiles and development of metabolic risk during the pubertal transition: a prospective study in the ELEMENT Project

OBJECTIVES

(1) Examine associations of a branched-chain amino acid (BCAA) metabolite pattern with metabolic risk across adolescence; (2) use Least Absolute Shrinkage and Selection Operator (LASSO) to identify novel metabolites of metabolic risk.

METHODS

We used linear regression to examine associations of a BCAA score with change (∆) in metabolic biomarkers over 5-year follow-up in 179 adolescents 8-14 years at baseline. Next, we applied LASSO, a regularized regression technique well suited for reduction of high-dimensional data, to identify metabolite predictors of ∆biomarkers.

RESULTS

In boys, the BCAA score corresponded with decreasing C-peptide, C-peptide-based insulin resistance (CP-IR), total cholesterol (TC), and low-density-lipoprotein cholesterol (LDL). In pubertal girls, the BCAA pattern corresponded with increasing C-peptide and leptin. LASSO identified asparagine as a predictor of decreasing C-peptide (β = -0.33) and CP-IR (β = -0.012), and acetyl-carnitine (β = 2.098), 4-hydroxyproline (β = -0.050), ornithine (β = -0.353), and α-aminoisobutyric acid (β = -0.793) as determinants of TC in boys. In girls, histidine was a negative determinant of TC (β = -0.033).

CONCLUSIONS

The BCAA pattern was associated with ∆glycemia and ∆lipids in a sex-specific manner. LASSO identified asparagine, which influences growth hormone secretion, as a determinant of decreasing C-peptide and CP-IR in boys, and metabolites on lipid metabolism pathways as determinants of decreasing cholesterol in both sexes.

The relationship between sleep duration and obesity risk among school students: a cross-sectional study in Zhejiang, China

Background

Obesity has been identified as a major risk factor for a large number of chronic diseases. Understanding factors related to adolescent obesity is critical for prevention of chronic diseases. The associations between sleep duration and obesity among adolescents in the existing literature are controversial. Our study was designed to determine the prevalence of short sleep duration, and assess the association of sleep duration and obesity, among middle and high school students in Zhejiang, China.

Methods

18,403 Students in 442 schools were recruited and surveyed using an anonymous, self-administered questionnaires. Weighted multivariable logistic regression models were used for data analyses.

Results

The mean (SD) age of the students was 15.9 (1.8) years. 49.7% of students were girls. The mean (SD) height and weight were 166.2 (8.5) cm and 54.6 (11.1) kg, respectively. The overall prevalence of obesity and overweight were 3.4% (95% CI: 3.0–3.8) and 7.8% (95% CI: 7.4–8.3), respectively. The overall prevalence of short sleep duration among students was 66.0% (95% CI: 63.8–68.1), higher among girls than boys (69.8% vs. 62.1%) (P < 0.0001). The figures for middle school, academic high school, and vocational high school were 59.0, 82.4 and 59.7%, respectively (P < 0.0001). As compared with girls who sleep 8 h per day (reference), the odds ratios (95% CI) of obesity for girls who sleep < 7 h, 7 h, 9 h and ≥ 10 h were 1.97 (1.15–3.38), 1.90 (1.18–3.04), 1.38 (0.86–2.20) and 2.12 (1.22–3.67) respectively, after adjustment for socio-demographic status, lifestyle factors, and mental health. The corresponding figures among boys were 1.45 (0.97–2.16), 1.13 (0.81–1.57), 1.25 (0.89–1.74), and 1.12 (0.81–1.54), respectively.

Conclusions

Insufficient sleep is prevalent among students in Zhejiang China. A U-shaped relationship was found between sleep duration and obesity risk among girls, with the lowest risk among those who slept for 8 h, but not among boys. Adequate sleep duration may be an important component of obesity prevention initiatives among adolescents.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0285-8) contains supplementary material, which is available to authorized users.

Vegetables and lean proteins-based and processed meats and refined grains -based dietary patterns in early childhood are associated with pubertal timing in a sex-specific manner: a prospective study of children from Mexico City

Childhood diet has been implicated in timing of sexual maturation. A key limitation of published studies is the focus on individual foods rather than patterns. We hypothesized that dietary patterns characterized by fruits and vegetables during early childhood (age 3 years) would be associated with delayed pubertal timing, whereas energy-dense and meat-based dietary patterns would relate to earlier puberty. The study population included 496 participants of a Mexico City birth cohort. The exposures of interest were dietary patterns derived from principal component analysis of dietary data collected via a semiquantitative food frequency questionnaire when the children were 3 years of age, and the outcomes were physician-assessed Tanner stages for pubic hair, breast (girls), genitalia, and testicular volume (boys) between 9 and 18 years, and initiation of menarche (girls). In regression analyses, we estimated adjusted hazard ratios and 95% confidence intervals for having reached Tanner stage ≥4 or initiation of menarche in girls and testicular volume ≥15 mL in boys. Among girls, those in the highest vs lowest tertile of vegetables and lean proteins pattern had a 35% (95% confidence interval 3%-67%) lower adjusted probability of having reached breast stage ≥4. Among boys, the processed meats and refined grain pattern score was associated with more advanced testicular development (adjusted hazard ratio = 3.58 [0.62-6.53]). Early childhood dietary patterns may play a role in the tempo of sexual maturation, which could ultimately carry implications for chronic disease susceptibility.

Maternal intake of omega-3 and omega-6 polyunsaturated fatty acids during mid-pregnancy is inversely associated with linear growth

This study investigates relations of maternal N-3 and N-6 polyunsaturated fatty acids (PUFA) intake during pregnancy with offspring body mass index (BMI), height z-score and metabolic risk (fasting glucose, C-peptide, leptin, lipid profile) during peripuberty (8-14 years) among 236 mother-child pairs in Mexico. We used food frequency questionnaire data to quantify trimester-specific intake of N-3 alpha-linolenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); N-6 linoleic acid and arachidonic acid (AA); and N-6:N-3 (AA:EPA+DHA), which accounts for the fact that the two PUFA families have opposing effects on physiology. Next, we used multivariable linear regression models that accounted for maternal education and parity, and child's age, sex and pubertal status, to examine associations of PUFA intake with the offspring outcomes. In models where BMI z-score was the outcome, we also adjusted for height z-score. We found that higher second trimester intake of EPA, DHA and AA were associated with lower offspring BMI and height z-score. For example, each 1-s.d. increment in second trimester EPA intake corresponded with 0.25 (95% CI: 0.03, 0.47) z-scores lower BMI and 0.20 (0.05, 0.36) z-scores lower height. Accounting for height z-score in models where BMI z-score was the outcome attenuated estimates [e.g., EPA: -0.16 (-0.37, 0.05)], suggesting that this relationship was driven by slower linear growth rather than excess adiposity. Maternal PUFA intake was not associated with the offspring metabolic biomarkers. Our findings suggest that higher PUFA intake during mid-pregnancy is associated with lower attained height in offspring during peripuberty. Additional research is needed to elucidate mechanisms and to confirm findings in other populations.