Effects of average childhood dairy intake on adolescent bone health

Innovative and Healthier Dairy Products through the Addition of Microalgae: A Review

In recent years, the development of healthier foods, richer in nutraceutical or functional compounds, has been in great demand. Microalgae are attracting increasing attention, as their incorporation in foods and beverages can be a promising strategy to develop sustainable foods with improved nutritional profiles and a strong positive impacts on health. Despite the increasing market demand in plant-based foods, the popularity of fermented dairy foods has increased in the recent years since they are a source of microorganisms with health-promoting effects. In this context, the incorporation of microalgae in cheeses, fermented milks and other dairy products represents an interesting approach towards the development of innovative and added-value hybrid products based on animal proteins and enriched with vegetable origin ingredients recognized as extremely valuable sources of bioactive compounds. The effect of the addition of microalgal biomass (Chlorella vulgaris, Arthrospira platensis, Pavlova lutheri, and Diacronema vlkianum, among others) and its derivates on the physicochemical composition, colorimetric and antioxidant properties, texture and rheology behavior, sensory profile, and viability of starter cultures and probiotics in yogurt, cheese and ice cream is discussed in the current work. This review of the literature on the incorporation of microalgae in dairy products aims to contribute to a better understanding of the potential use of these unique food ingredients in the development of new sustainable products and of their beneficial effects on health. Considering the importance of commercialization, regulatory issues about the use of microalgae in dairy products are also discussed.

Double burden of malnutrition in ethnic minority school-aged children living in mountainous areas of Vietnam and its association with nutritional behavior

BACKGROUND/OBJECTIVES

Although children of ethnic minority groups are experiencing a transition from a predominance of undernutrition to overnutrition, there is little evidence of a dual-malnutrition burden. Therefore, this study examined the double burden of malnutrition among school-aged ethnic minority children living in mountainous areas and its association with their diets.

SUBJECTS/METHODS

A cross-sectional study was conducted from September 2019 to March 2020 in 3 mountainous areas of Northern Vietnam among 1,556 ethnic minority school-aged children. The prevalence of under-nutrition (stunting and thinness) and over-nutrition (overweight and obesity) were measured using the WHO 2006 child growth standards (height-for-age and BMI-for-age Z-score). Nutritional practices were evaluated by the frequency of food consumption based on a 4-level scale.

RESULTS

The percentage of children with stunting and thinness were 14.0% and 5.4%, respectively, while the figure for overweight/obesity was 9.4%. The factors positively associated with stunting were living in a family with more than 2 children or being Muong/other ethnicities compared to the Tay ethnicity. Children who consumed fish/shrimps/crabs or milk weekly/daily were less likely to be undernourished compared to those who never consumed these foods. By contrast, children who never consumed foods rich in vitamin A precursors and vitamin A and fruit or consumed daily snacks/junk food were more likely to be overweight/obese.

CONCLUSIONS

Undernutrition remains a common issue among school-aged children and adolescents of ethnic minority groups, while over-nutrition exists simultaneously. Public health nutrition programs promoting adequate diets and positive lifestyle changes related to nutrition are essential to tackle the double burden of malnutrition among ethnic minority children.

The associations between serum trace elements and bone mineral density in children under 3 years of age

We examined the associations of age and serum magnesium, iron, lead, copper, and zinc levels with bone mineral density (BMD) in 2412 children under 3 years of age in order to find a tool to monitor BMD in children without the use of expensive imaging techniques. One-way ANOVA and chi-square tests were used to determine the associations of age and serum trace elements with BMD. Multivariable logistic regression analysis was used to test the correlation of five serum trace elements with BMD after adjustments for potential confounding factors in children under 3 years of age. Significant associations between age and four serum trace elements and BMD were found. Compared to the group with the lowest serum levels detected, the adjusted odds ratio (OR) for the incidence of normal bone mineral density in the third magnesium concentration tertile, the third iron concentration tertile, the fifth copper concentration quintile, the third zinc concentration quintile, and the fifth zinc concentration quintile were 1.30 (95% confidence interval (CI) 1.02–1.67), 1.43 (95% CI 1.11–1.84), 1.42 (95% CI 1.04–1.94), 1.46 (95% CI 1.05–2.04), and 1.48 (95% CI 1.06–2.06), respectively. However, there was no significant correlation between serum lead level and BMD in this study. Age and serum magnesium, iron, copper, and zinc levels are positively associated with BMD in children under 3 years old.

Invited review: Maintaining and growing fluid milk consumption by children in school lunch programs in the United States

Fluid milk consumption among children has declined for decades. Adequate consumption of milk and dairy products, especially during childhood, has beneficial health outcomes for growth, development, and reduced risk of osteoporosis, hypertension, obesity, and cancer during adulthood. Satisfaction with milk flavor, perceived health benefits derived from milk, and habit are primary drivers of lifelong milk consumption. Child preferences and attitudes for milk may differ from those of adults, and as such, understanding and fulfilling the needs of children is crucial to reverse the decline in milk consumption. School meal programs make fluid milk accessible to millions of children each day; however, regulations and school lunch procurement systems in the United States sometimes make it difficult to provide novel or value-added milk products in these programs. Total consumption of all milk types in US schools declined by 14.2% from 2008 to 2017, and the percentage of children participating in the school lunch program has also declined. This decline has also been driven by declining average daily participation in the school meal program and may also reflect children's dissatisfaction with the sensory characteristics and the form of milk offered in schools. The change in form of milk offered in schools to lower fat and lower added sugar content in the United States has been driven by government-mandated school lunch calorie and fat requirements. This review describes the current milk consumption trends among children; the structure and basic requirements of the school lunch program in total and for milk; and the intrinsic, extrinsic, and environmental factors that influence child perception, preference, and consumption of fluid milk in the US school system.

Milk Consumption for the Prevention of Fragility Fractures

Results indicating that a high milk intake is associated with both higher and lower risks of fragility fractures, or that indicate no association, can all be presented in the same meta-analysis, depending on how it is performed. In this narrative review, we discuss the available studies examining milk intake in relation to fragility fractures, highlight potential problems with meta-analyses of such studies, and discuss potential mechanisms and biases underlying the different results. We conclude that studies examining milk and dairy intakes in relation to fragility fracture risk need to study the different milk products separately. Meta-analyses should consider the doses in the individual studies. Additional studies in populations with a large range of intake of fermented milk are warranted.

Effects of Milk and Milk-Product Consumption on Growth among Children and Adolescents Aged 6-18 Years: A Meta-Analysis of Randomized Controlled Trials

Although studies have suggested that milk and milk-product consumption may influence growth during childhood and puberty, results are inconsistent. This meta-analysis was performed to evaluate the available evidence of randomized controlled trials (RCTs) assessing whether milk and milk-product consumption could affect growth and body composition among children and adolescents aged 6-18 y. PubMed, EMBASE, Web of Science, and The Cochrane Library databases were systematically searched for all RCTs published up to December 2017 that investigated milk and milk-product consumption (≥12 wk) on growth and body composition among participants (aged 6-18 y) without undernourishment or diseases. Study screening and data extraction by 2 reviewers followed established PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The Cochrane Collaboration's tool was used to assess the quality of the trials. Data were pooled using a random-effects model. Seventeen trials with 2844 children and adolescents were included. Milk and milk-product interventions resulted in a greater increase in body weight (0.48 kg; 95% CI: 0.19, 0.76 kg; P  =  0.001), lean mass (0.21 kg; 95% CI: 0.01, 0.41 kg; P  = 0.04), and attenuated gain in percentage body fat (-0.27%; 95% CI: -0.45%, -0.09%; P  = 0.003) compared with control groups. However, there were no significant changes in fat mass, height, or waist circumference in the intervention groups compared with the control groups (P ≥ 0.05). In subgroup analyses, the baseline weight and age, and the duration of intervention were associated with the efficacy of milk and milk-product intake on the change in lean mass, percentage body fat, and waist circumference, respectively (test for subgroup differences: P < 0.05). Children and adolescents aged 6-18 y consuming milk and milk products are more likely to achieve a lean body phenotype. This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018086850.

Whole egg consumption and cortical bone in healthy children

Eggs contain bioactive compounds thought to benefit pediatric bone. This cross-sectional study shows a positive link between childhood egg intake and radius cortical bone. If randomized trials confirm our findings, incorporating eggs into children's diets could have a significant impact in preventing childhood fractures and reducing the risk of osteoporosis.

INTRODUCTION

This study examined the relationships between egg consumption and cortical bone in children.

METHODS

The cross-sectional study design included 294 9-13-year-old black and white males and females. Three-day diet records determined daily egg consumption. Peripheral quantitative computed tomography measured radius and tibia cortical bone. Body composition and biomarkers of bone turnover were assessed using dual-energy X-ray absorptiometry and ELISA, respectively.

RESULTS

Egg intake was positively correlated with radius and tibia cortical bone mineral content (Ct.BMC), total bone area, cortical area, cortical thickness, periosteal circumference, and polar strength strain index in unadjusted models (r = 0.144-0.224, all P < 0.050). After adjusting for differences in race, sex, maturation, fat-free soft tissue mass (FFST), and protein intakes, tibia relationships were nullified; however, egg intake remained positively correlated with radius Ct.BMC (r = 0.138, P = 0.031). Egg intake positively correlated with total body bone mineral density, BMC, and bone area in the unadjusted models only (r = 0.119-0.224; all P < 0.050). After adjusting for covariates, egg intake was a positive predictor of radius FFST (β = 0.113, P < 0.050) and FFST was a positive predictor of Ct.BMC (β = 0.556, P < 0.050) in path analyses. There was a direct influence of egg on radius Ct.BMC (β = 0.099, P = 0.035), even after adjusting for the mediator, FFST (β = 0.137, P = 0.020). Egg intake was positively correlated with osteocalcin in both the unadjusted (P = 0.005) and adjusted (P = 0.049) models.

CONCLUSION

If the positive influence of eggs on Ct.BMC observed in this study is confirmed through future randomized controlled trials, whole eggs may represent a viable strategy to promote pediatric bone development and prevent fractures.

Are consumption of dairy products and physical activity independently related to bone mineral density of 6-year-old children? Longitudinal and cross-sectional analyses in a birth cohort from Brazil

OBJECTIVE

To evaluate cross-sectional and longitudinal associations of consumption of dairy products and physical activity (PA) with bone mineral density (BMD).

DESIGN

Cohort study with children from the 2004 Pelotas (Brazil) Birth Cohort.

SETTING

Pelotas, a medium-sized Brazilian city.

SUBJECTS

The study started in 2004 and mothers/children were interviewed/measured periodically from birth to age 6 years. PA was measured by maternal proxy at 4 and 6 years and by accelerometry at 6 years. Consumption of dairy products was measured using 24 h food recall (at 4 years) and FFQ (at 6 years). Total-body and lumbar-spine BMD (g/cm2) were measured by dual-energy X-ray absorptiometry.

RESULTS

At 6 years, BMD was measured in 3444 children and 2636 children provided data on objectively measured PA by accelerometry. Consumption of dairy products at 4 years was associated with higher lumbar-spine BMD at 6 years in boys, while current consumption was positively associated with BMD in both sexes (P < 0·001). PA assessed by maternal report at 4 and 6 years of age was associated with higher BMD at 6 years in boys. PA assessed by accelerometry was positively related to total-body and lumbar-spine BMD in boys and lumbar-spine BMD in girls. We did not find evidence for an interaction between PA and consumption of dairy products on BMD.

CONCLUSIONS

We observed positive and independent longitudinal and cross-sectional associations between consumption of dairy products and PA with BMD in the total body and at the lumbar spine in young children.

Soy Protein Isolate Suppresses Bone Resorption and Improves Trabecular Microarchitecture in Spontaneously Hyperphagic, Rapidly Growing Male OLETF Rats

BACKGROUND

Traditionally, milk proteins have been recommended for skeletal health; recently, soy proteins have emerged as popular alternatives. Excess adiposity appears detrimental to skeletal health, as obese adolescents have increased fracture rates compared with healthy controls. However, soy protein effects on skeletal health during excess adiposity remain unknown.

OBJECTIVE

The study objective was to examine the effects of isocaloric diets containing milk protein isolate (MPI), soy protein isolate (SPI), or a 50/50 combination (MIX) as the sole protein source on metabolic health indicators and bone outcomes in rapidly growing, hyperphagic, male Otsuka Long Evans Tokushima Fatty (OLETF) rats.

METHODS

OLETF rats, aged 4 wk, were randomly assigned to 3 treatment groups (MPI, SPI, or MIX, n = 20 per group) and provided with access to experimental diets ad libitum for 16 wk.

RESULTS

Body mass did not differ between the groups, but SPI had lower percentage body fat than MPI (P = 0.026). Insulin was lower in MPI than in MIX (P = 0.033) or SPI (P = 0.044), but fasting blood glucose was not different between the groups. SPI significantly reduced serum cholesterol compared with MPI (P = 0.001) and MIX (P = 0.002). N-terminal propeptide of type I collagen (P1NP) was higher in MIX than MPI (P = 0.05); C-terminal telopeptide of type 1 collagen (CTx) was higher in MPI than SPI (P < 0.001) and MIX (P < 0.001); the P1NP to CTx ratio was significantly higher in SPI and MIX than in MPI (P < 0.001). Trabecular separation was reduced in SPI compared with MPI (P = 0.030) and MIX (P = 0.008); trabecular number was increased in SPI compared with MIX (P = 0.038). No differences were seen in cortical geometry and biomechanical properties.

CONCLUSIONS

In the context of excess adiposity, soy- and milk-based proteins have comparable effects on cortical bone geometry and biomechanical properties, whereas soy-based proteins favorably affect the trabecular microarchitecture, and the combination of both proteins may offer additional benefits to bone remodeling in rapidly growing male OLETF rats.

Strategies for public health initiatives targeting dairy consumption in young children: a qualitative formative investigation of parent perceptions

OBJECTIVE

Dairy products contain essential nutrients to ensure healthy growth and bone development in children. However, a significant proportion of children in developed countries fail to consume the daily recommended intake of dairy products. Parents are the gatekeepers of familial nutritional intake and represent a potential vehicle through which to increase dairy consumption in children. As such, formative research was conducted to gain insight into parents' perceived barriers to and benefits of purchasing and consuming dairy products and to develop innovative message content that could be utilized in future public health campaigns.

DESIGN

Seven in-depth group interviews were conducted in two phases between February and May 2015.

SETTING

Interviews were conducted in local recreational centres and libraries in British Columbia, Canada.

SUBJECTS

Mothers (n 21, mean age 38 (sd 5) years) and fathers (n 9, mean age 38 (sd 3) years) of children aged 4-10 years.

RESULTS

Parents perceived both positive and negative physical outcomes associated with consuming dairy. Lack of trustworthy information was a frequently discussed barrier theme to purchasing and consuming dairy products. Mothers were concerned about the cost of dairy products. Differences in purchasing and consumption strategies were reported between parents of children who consumed adequate dairy and those who did not. Parents believed the most appropriate communication channel was through print material.

CONCLUSIONS

Messages targeting parents, as a means of increasing dairy consumption in children, should address barriers identified by parents. In addition, practical tips should be provided to promote purchasing and consumption of dairy products.

Dietary sources and sociodemographic and lifestyle factors affecting vitamin D and calcium intakes in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study

Objective

To investigate dietary sources of Ca and vitamin D (VitD) intakes, and the associated sociodemographic and lifestyle factors, among European adolescents.

Design

Linear regression mixed models were used to examine sex-specific associations of Ca and VitD intakes with parental education, family affluence (FAS), physical activity and television (TV) watching while controlling for age, Tanner stage, energy intake and diet quality.

Setting

The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA)Cross-Sectional Study.

Subjects

Adolescents aged 12·5–17·5 years (n 1804).

Results

Milk and cheese were the main sources of Ca (23 and 19 % contribution to overall Ca intake, respectively). Fish products were the main VitD source (30 % contribution to overall VitD intake). Ca intake was positively associated with maternal education (β=56·41; 95 % CI 1·98, 110·82) and negatively associated with TV viewing in boys (β=–0·43; 95 % CI −0·79, −0·07); however, the significance of these associations disappeared when adjusting for diet quality. In girls, Ca intake was positively associated with mother’s (β=73·08; 95 % CI 34·41, 111·74) and father’s education (β=43·29; 95 % CI 5·44, 81·14) and FAS (β=37·45; 95 % CI 2·25, 72·65). This association between Ca intake and mother’s education remained significant after further adjustment for diet quality (β=41·66; 95 % CI 0·94, 82·38). Girls with high-educated mothers had higher Ca intake.

Conclusions

Low-educated families with poor diet quality may be targeted when strategizing health promotion programmes to enhance dietary Ca.

Barriers and Facilitators to Intake of Dairy Products in Adolescent Males and Females With Different Levels of Habitual Intake

Background: Dairy products and alternatives can contribute to overall good health including positive body composition and decreased adiposity; however, these foods are grossly underconsumed by youth, and worldwide, almost 25% of children are overweight or obese. Objective: The study investigated the barriers and facilitators toward dairy consumption by Grade 7 youth. Methods: Thirty 50-minute, audio-recorded focus groups were conducted with 134 students in eight Grade 7 classes across 5 elementary schools. Focus groups were led by trained facilitators in the elementary schools and participants were separated based on dairy consumption and gender. Recorded data were transcribed and thematically analyzed using qualitative analysis software to identify themes related to barriers and facilitators to dairy product intake by each gender. Results: Factors considered important by males and females across different levels of habitual intake include personal knowledge about dairy products and misconceptions regarding dairy foods and their associated health benefits; food characteristics, including taste; personal behaviors such as habits or routines including dairy products; social environments including parental and peer influence; physical environments factors such as availability and skipping meals; and the convenience of dairy products. Interestingly, only males noted sports as a positive influence for dairy product intake. Also, there were differences in the way males and females perceived dining out as affecting their dairy intake. Conclusion: Results suggest several potential factors that nutrition education interventions aiming to increase dairy consumption could target.

Interventions to Increase Dairy Consumption in Adolescents

Objective. Effective interventions are needed to address the reported inadequacies of dairy product and calcium (Ca) intakes among adolescents. The present review investigated interventions aimed at increasing adolescent dairy and/or Ca intakes and determined the characteristics associated with successful interventions. Design. A PRISMA systematic review search identified 17 interventions, described in 16 publications, between 1993 and 2015 (February). Studies were evaluated for population, delivery, dietary targets and outcomes measures, measure of intervention intensity, use of behavior change techniques, intervention effectiveness, and effect size and quality. Setting. Interventions targeting an increase in dairy food or Ca intake, either exclusively or in combination with other dietary modifications. Subjects. Adolescents, aged 12 to 18 years. Results. Twelve of the 17 interventions were found to be effective. Effective interventions tended to be higher in overall intensity (mean intensity: negative interventions 12.2, positive interventions 14.25), with the most notable difference in the duration category, such that effective interventions tended to be longer in duration. The number of behavior change techniques applied did not differentiate effective and ineffective interventions, but prompting the review of behavioral goals and including interviews or brief counseling appeared to be important for effective interventions. Effective interventions tended to have higher methodological quality, while the majority of ineffective interventions were qualitatively assessed as weak. Conclusions. The current review has identified characteristics of effective interventions that offer insight into promising strategies likely to increase dairy consumption and Ca intakes in countries where adolescent intake is insufficient. These findings may have important implications for future intervention design.

The influence of dairy consumption and physical activity on ultrasound bone measurements in Flemish children

The study's aim was to analyse whether children's bone status, assessed by calcaneal ultrasound measurements, is influenced by dairy consumption and objectively measured physical activity (PA). Moreover, the interaction between dairy consumption and PA on bone mass was studied. Participants of this cross-sectional study were 306 Flemish children (6-12 years). Body composition was measured with air displacement plethysmography (BodPod), dairy consumption with a Food Frequency Questionnaire, PA with an accelerometer (only in 234 of the 306 children) and bone mass with quantitative ultrasound, quantifying speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness Index (SI). Regression analyses were used to study the associations between dairy consumption, PA, SOS, BUA and SI. Total dairy consumption and non-cheese dairy consumption were positively associated with SOS and SI, but no significant association could be demonstrated with BUA. In contrast, milk consumption, disregarding other dairy products, had no significant effect on calcaneal bone measurements. PA [vigorous PA, moderate to vigorous physical activity (MVPA) and counts per minute] was positively associated and sedentary time was negatively associated with BUA and SI, but no significant influence on SOS could be detected. Dairy consumption and PA (sedentary time and MVPA) did not show any interaction influencing bone measurements. In conclusion, even at young age, PA and dairy consumption positively influence bone mass. Promoting PA and dairy consumption in young children may, therefore, maximize peak bone mass, an important protective factor against osteoporosis later in life.

Intake patterns and dietary associations of soya protein consumption in adults and children in the Canadian Community Health Survey, Cycle 2.2

Soya foods are one of the recommended alternatives to meat in many dietary guidelines. While this is expected to increase the intake of some nutrients, potential concerns regarding others have been raised. The purpose of the present study was to examine the prevalence and the association of soya food consumption with nutrient intakes and dietary patterns of Canadians (age ≥ 2 years). Cross-sectional data from the 2004 Canadian Community Health Survey (Cycle 2.2; n 33 218) were used to classify soya consumers and non-consumers. Soya consumers were further divided into two groups based on their soya protein intake. Sample weights were applied and logistic regression analysis was used to explore the association between nutrient intakes and soya consumption, with cultural background, sex, age and economic status being included as covariates. On any given day, 3·3 % (n 1085) of Canadians consume soya foods, with females, Asian Canadians and adults with post-secondary education being more likely to be soya consumers. As a whole, adolescent and adult respondents who had consumed at least one soya food during their 24 h dietary recall had higher energy intakes, as well as increased intakes of nutrients such as protein, fibre, vitamin C, vitamin B6, naturally occurring folate, thiamin, Ca, P, Mg, PUFA, Fe and K and lowered intakes of saturated fat. These data indicate that soya food consumption is associated with improved diet quality of Canadians. However, future research is necessary to investigate the association between increased energy intake and soya consumption.

Evaluation of tools used to measure calcium and/or dairy consumption in adults

OBJECTIVE

To identify and critique tools for the assessment of Ca and/or dairy intake in adults, in order to ascertain the most accurate and reliable tools available.

DESIGN

A systematic review of the literature was conducted using defined inclusion and exclusion criteria. Articles reporting on originally developed tools or testing the reliability or validity of existing tools that measure Ca and/or dairy intake in adults were included. Author-defined criteria for reporting reliability and validity properties were applied.

SETTING

Studies conducted in Western countries.

SUBJECTS

Adults.

RESULTS

Thirty papers, utilising thirty-six tools assessing intake of dairy, Ca or both, were identified. Reliability testing was conducted on only two dairy and five Ca tools, with results indicating that only one dairy and two Ca tools were reliable. Validity testing was conducted for all but four Ca-only tools. There was high reliance in validity testing on lower-order tests such as correlation and failure to differentiate between statistical and clinically meaningful differences. Results of the validity testing suggest one dairy and five Ca tools are valid. Thus one tool was considered both reliable and valid for the assessment of dairy intake and only two tools proved reliable and valid for the assessment of Ca intake.

CONCLUSIONS

While several tools are reliable and valid, their application across adult populations is limited by the populations in which they were tested. These results indicate a need for tools that assess Ca and/or dairy intake in adults to be rigorously tested for reliability and validity.

Intakes of selected nutrients, bone mineralisation and density of adolescent female swimmers over a three-year period

The aim of this study was to conduct three-year monitoring of bone mineralization (BMC) and bone mineral density (BMD) of adolescent girls engaged in swimming at the time of attaining the peak bone mass and of their counterparts leading a rather sedentary life, considering the intakes of calcium, phosphorus and protein, as well as the proportions among those nutrients. Two groups of girls aged 11-13 years were studied 3 times at yearly intervals: untrained controls (n = 20) and those engaged in competitive swimming (n = 20). Bone density was determined by dual-energy X-ray absorptiometry (DXA) in the lumbar spine (L2 - L4). Nutrient intakes (energy, protein, calcium, phosphorus) were assessed from 24-h recalls. The group of swimmers had significantly lower BMI values than the control group. No systematic, significant between-group differences were found in nutrient intake or in bone mineralization variables. Calcium intake was below the recommended norm in all subjects but mean values of bone mineralization variables (BMC, BMD) steadily increased in both groups. The BMD z-scores proved negative throughout the three-year period of early adolescence in both groups of girls and that decrease was significant in swimmers. This could have been due to insufficient calcium intake as well as to inadequate calcium-to-phosphate and protein-to-calcium ratios and, when continued, might result in a decreased bone mass in adulthood.

Associations of dietary calcium, vitamin D, milk intakes, and 25-hydroxyvitamin D with bone mass in Spanish adolescents: the HELENA study

Adequate nutrition is needed for the accrual of bone mass during the pre- and postpubertal growth periods. This study aimed to examine the associations between dietary calcium, vitamin D (calciferol), and milk intakes and 25-hydroxyvitamin D [25(OH)D] status and bone mineral content (BMC) and bone mineral density (BMD) in Spanish adolescents, aged 12.5-17.5 years, participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS). Bone mass was measured with dual-energy X-ray absorptiometry and diet via 2 nonconsecutive 24-h dietary recalls (n=227; 48% males). A random subsample of 101 adolescents (46% males) had available measures of 25(OH)D. Multiple linear regression was applied. Significant adjusted associations were observed in males, among milk intakes and BMC and BMD. Also in males, whole-body, head, and right arm BMD were positively related to calcium intakes. In females, 25(OH)D was positively related among others to whole-body, subtotal, and left and right arm BMC and BMD. It could be speculated that diet is not a limiting factor of bone mass development in this group of healthy adolescents, and further research on the effect of other factors in addition to diet in a larger sample should be undertaken.

A milk and cereal dietary pattern is associated with a reduced likelihood of having a low bone mineral density of the lumbar spine in Korean adolescents

The traditional rice-based Korean diet has been changing toward a Western-style diet. This change has been especially rapid among adolescents. The purpose of this study was to investigate the association between dietary patterns and bone health among Korean adolescents. This cross-sectional study was conducted on 196 adolescents aged 12 to 15 years. Information on the general characteristics of the subjects was obtained through a questionnaire, and dietary intake was assessed with 6-day food records. Bone mineral densities (BMDs) of the lumbar spine and femur were measured by dual-energy x-ray absorptiometry. Dietary patterns were derived from 24 food groups using factor analysis. Four distinct dietary patterns-traditional Korean, fast food, milk and cereal, and snacks-were identified and accounted for 28.4% of the total variance. After adjusting for sex, age, body mass index percentiles, weight loss attempts, pubertal status, and regular exercise, the adolescents in the highest tertile of the "milk and cereal" dietary pattern score had significantly a reduced likelihood of having low BMD compared with those in the lowest tertile of this diet at the lumbar spine (odds ratio, 0.36; 95% confidence interval, 0.14-0.93; P = .0461). The other dietary patterns were not associated with the BMD of Korean adolescents. These results indicate that the intake of milk and cereal is important for the bone health of Korean adolescents, whose diets are composed mainly of grains and vegetables.

Food group intake and micronutrient adequacy in adolescent girls

This study explores the contribution of food group intakes to micronutrient adequacy among 2379 girls in the National Growth and Health Study during three age periods (9–13, 14–18, and 19–20 years). Data on food and nutrient intakes from 3-day diet records over 10 years were used to estimate mean intakes and percent meeting Dietary Guidelines (DGA) recommendations for food intakes and Institute of Medicine’s recommendations for vitamins and minerals. More than 90% of girls failed to consume the recommended amounts of fruit, vegetables and dairy; 75% consumed less than the recommended amounts in the “meat” group. The vast majority of girls of all ages had inadequate intakes of calcium, magnesium, potassium, and vitamins D and E. In contrast, they consumed >750 kcal/day (~40% of total energy) from the DGA category of solid fat and added sugars, about five times the recommended maximum intakes. This study shows the importance of consuming a variety of foods in all five food groups, including those that are more energy dense such as dairy and meats, in order to meet a broad range of nutrient guidelines. Diet patterns that combined intakes across food groups led to greater improvements in overall nutritional adequacy.

Associations between flavored milk consumption and changes in weight and body composition over time: differences among normal and overweight children

BACKGROUND/OBJECTIVES

Few studies have investigated the associations between flavored milk consumption and body composition in children. We aimed to examine the prospective relationships between flavored milk consumption and body fat.

SUBJECTS/METHODS

Subjects included 2270 children from the Avon Longitudinal Study of Parents and Children. Flavored milk consumption at age 10 years was assessed using dietary records; consumption was dichotomized as consumers and non-consumers. Percent body fat was measured using dual-energy X-ray absorptiometry at 11 and 13 years. Body weight at 11 and 13 years was included as a secondary outcome. Associations were also examined in a subset of plausible reporters to evaluate the influence of dietary reporting errors. There was an effect of interaction between flavored milk and baseline weight on body fat (P-interaction <0.02).

RESULTS

In plausible reporters, overweight/obese children who consumed flavored milk had less favorable changes in body fat compared with non-consumers (adjusted means: -0.16%, 95% CI: -3.8, 3.5 vs -3.4%, 95% CI: -6.5, -0.42, P=0.02). Similar associations with body weight were observed. The adjusted mean percent body fat for overweight/obese girls who consumed flavored milk was greater at age 13 compared with 11 years (39.7%, 95% CI: 32, 47 vs 38.3%, 95% CI: 32, 44). The mean percent body fat for overweight/obese boys was similar between consumers and non-consumer is at 13 years (30.4%, 95% CI: 20, 41 vs 30.1%, 95% CI: 21, 40).

CONCLUSIONS

Overweight/obese children who consumed flavored milk had less favorable changes in body composition over time. Although more research is needed, discouraging flavored milk consumption may be one beneficial strategy to address childhood obesity.

Relations of diet and physical activity to bone mass and height in black and white adolescents

Because the development of healthy bodies during the years of growth has life-long health consequences, it is important to understand the early influences of diet and physical activity (PA). One way to generate hypotheses concerning such influences is to conduct cross-sectional studies of how diet and PA are related to different components of body composition. The subjects were 660 black and white adolescents. Total body bone mineral content (BMC) was measured with dual-energy X-ray absorptiometry; free-living diet and PA were assessed with 4-7 separate 24-h recalls. The main dietary variables investigated were: total energy intake, macronutrient distribution (%), dairy servings, vitamin D, and calcium. The main PA variables were hours of moderate PA (3-6 METs) and vigorous PA (>6 METs). BMC was higher in blacks than in whites (P<0.01) and it increased more in boys than in girls (age by sex interaction) as age increased (P<0.01). After adjustment for age, race and sex, higher levels of BMC were associated with higher levels of energy intake, dairy servings, calcium, vitamin D, and vigorous PA (all P 's<0.05). In the multivariable model, significant and independent proportions of the variance in BMC were explained by race, the age by sex interaction, calcium, and vigorous PA (all P 's<0.01). When height was used as the outcome variable, similar diet results were obtained; however, there was a sex by vigorous PA interaction, such that vigorous PA was associated with height only in the girls. These data are consistent with the hypothesis that the bone mass and height of growing youths are positively influenced by higher dietary intake of energy and dairy foods, along with sufficient amounts of vigorous PA. This hypothesis needs to be tested in randomized controlled trials.

Body composition and bone mineral density in children with premature adrenarche and the association of LRP5 gene polymorphisms with bone mineral density

CONTEXT

Precocious increase in adrenal androgen production is the hallmark of premature adrenarche (PA). Adrenal androgens have anabolic properties.

OBJECTIVE

The objective of the study was to test whether body composition and bone mineral density (BMD) are altered in PA and study whether genetic variation in low-density lipoprotein receptor-related protein 5 (LRP5) affects BMD in PA.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at a university hospital.

SUBJECTS AND MEASURES

The study included 126 prepubertal children (64 with PA, 10 boys; 62 non-PA controls, 10 boys). Femoral neck and lumbar spine areal and calculated volumetric BMD (dual energy X-ray absorptiometry), body composition (bioimpedance), serum 25-hydroxyvitamin D, and markers of bone turnover and calcium homeostasis were compared between the PA and control groups. Single-nucleotide polymorphisms of LRP5 were determined and associated with BMD.

RESULTS

Children with PA had higher femoral neck and lumbar spine BMD(areal) than the controls (Z-score 0.56 vs. -0.09, P < 0.001, and 0.20 vs. -0.31, P = 0.009, respectively). However, the mean BMDs did not differ significantly between the groups when adjusted for height or bone size. BMD(areal) correlated strongly with height sd score in both groups. Among the PA children, LRP5 single-nucleotide polymorphism E644E minor variant was associated with lower and F549F minor variant with higher BMD. Total body fat mass, fat percent, serum PTH, and alkaline phosphatase concentrations were higher and 25-hydroxyvitamin D lower in the PA group.

CONCLUSIONS

Prepubertal children with PA had higher BMD(areal) compared with healthy controls. This was mainly explained by their increased height. LRP5 polymorphisms may contribute to bone mass accrual in prepubertal PA children.