Bidirectional associations between diet and body composition measures from 2 to 15 years: Longitudinal Study of Australian Children

Health behaviours associated with healthy body composition among Aboriginal adolescents in Australia in the 'Next Generation: Youth Well-being study'

This study described the distribution of healthy body composition among Aboriginal adolescents in Australia aged 10-24 years and examined associations with health behaviours and self-rated health. Data were cross-sectional from the 'Next Generation: Youth Well-being study' baseline (N = 1294). We used robust Poisson regression to quantify associations of self-reported health behaviours (physical activity, screen time, sleep, consumption of vegetables, fruit, soft drinks and fast food, and tobacco smoking and alcohol) and self-rated health to healthy body mass index (BMI) and waist/height ratio (WHtR). Overall, 48% of participants had healthy BMI and 64% healthy WHtR, with healthy body composition more common among younger adolescents. Higher physical activity was associated with healthy body composition (5-7 days last week vs none; adjusted prevalence ratio (aPR) healthy BMI 1.31 [95% CI 1.05-1.64], and healthy WHtR 1.30 [1.10-1.54]), as was recommended sleep duration (vs not; aPR healthy BMI 1.56 [1.19-2.05], and healthy WHtR 1.37 [1.13-1.67]). There was a trend for higher proportion of healthy body composition with more frequent fast food consumption. Healthy body composition was also associated with higher self-rated health ('very good/excellent' vs 'poor/fair'; aPR healthy BMI 1.87 [1.45-2.42], and healthy WHtR 1.71 [1.40-2.10]). Culturally appropriate community health interventions with a focus on physical activity and sleep may hold promise for improving body composition among Aboriginal adolescents.

The association between dietary trajectories across childhood and blood pressure in early adolescence: The Longitudinal Study of Australian Children

BACKGROUND

Cardio-metabolic risk factors, including hypertension, are increasingly appearing in childhood. The aims of this study were to examine the associations between dietary trajectories across childhood and subsequent blood pressure (BP) at age 10/11, and to further determine whether these associations were explained by BMI or fat mass.

METHODS

Data from 4360 participants from the Longitudinal Study of Australian Children were analysed. Dietary scores were computed based on similarity of intake to the Australian Dietary Guidelines. Group-based trajectory modelling was used to identify distinct dietary trajectories based on participant's individual dietary scores at up to four timepoints between age 4 and 11. Linear regression models examined the associations between dietary trajectories and BP measured at age 10/11. Models were adjusted for relevant covariates, and BMI or fat mass.

RESULTS

Four dietary trajectories were identified: "never healthy" (4.3%); "moderately healthy" (23.1%); "becoming less healthy" (14.2%); and "always healthy" (58.4%). Children in the "always healthy" trajectory had a lower systolic (-2.19 mmHg; 95% CI -3.78, -0.59) and diastolic BP (-1.71; -2.95, -0.47), compared with children in the "never healthy" trajectory after covariate adjustment. These associations were attenuated after additional adjustment for BMI or fat mass, but remained significant for diastolic BP.

CONCLUSIONS

A dietary trajectory mostly aligned with the Australian Dietary Guidelines across childhood was associated with slightly lower BP at age 10/11, which was not fully explained by BMI or fat mass. These findings support the need to encourage and enable healthy dietary habits early in childhood to attenuate the increasing burden of cardio-metabolic disease.

Can adult polygenic scores improve prediction of body mass index in childhood?

BACKGROUND/OBJECTIVES

Modelling genetic pre-disposition may identify children at risk of obesity. However, most polygenic scores (PGSs) have been derived in adults, and lack validation during childhood. This study compared the utility of existing large-scale adult-derived PGSs to predict common anthropometric traits (body mass index (BMI), waist circumference, and body fat) in children and adults, and examined whether childhood BMI prediction could be improved by combining PGSs and non-genetic factors (maternal and earlier child BMI).

SUBJECTS/METHODS

Participants (n = 1365 children, and n = 2094 adults made up of their parents) were drawn from the Longitudinal Study of Australian Children. Children were weighed and measured every two years from 0-1 to 12-13 years, and adults were measured or self-reported measurements were obtained concurrently (average analysed). Participants were genotyped from blood or oral samples, and PGSs were derived based on published genome-wide association studies. We used linear regression to compare the relative utility of these PGSs to predict their respective traits at different ages.

RESULTS

BMI PGSs explained up to 12% of child BMI z-score variance in 10-13 year olds, compared with up to 15% in adults. PGSs for waist circumference and body fat explained less variance (up to 8%). An interaction between BMI PGSs and puberty (p = 0.001-0.002) suggests the effect of some variants may differ across the life course. Individual BMI measures across childhood predicted 10-60% of the variance in BMI at 12-13 years, and maternal BMI and BMI PGS each added 1-9% above this.

CONCLUSION

Adult-derived PGSs for BMI, particularly those derived by modelling between-variant interactions, may be useful for predicting BMI during adolescence with similar accuracy to that obtained in adulthood. The level of precision presented here to predict BMI during childhood may be relevant to public health, but is likely to be less useful for individual clinical purposes.

Nutrition beyond the first 1000 days: diet quality and 7-year change in BMI and overweight in 3-year old children from the Dutch GECKO Drenthe birth cohort

The identification of early-life determinants of overweight is crucial to start early prevention. As weight gain accelerates between 2 and 6 years, we studied the association between diet quality in children aged 3 years and the change in BMI and overweight incidence in the following 7 years. From the Dutch GECKO Drenthe birth cohort, 1001 children born in 2006 or 2007 with complete data on diet (food frequency questionnaire at the age of 3 years) and growth at the age of 3 and 10 years were included. Diet quality was estimated with the evidence-based Lifelines Diet Score (LLDS). Measured height and weight at the age of 3 and 10 years were used to calculate BMI z-scores standardized for age and sex. The associations of the LLDS (in quintiles) with BMI-z change and overweight incidence were studied with linear and logistic regression analyses. Overweight prevalence in the total study population increased from 8.3% at the age of 3 years to 16.7% at the age of 10 years. The increase in overweight prevalence ranged from 14.7% in Q1 to 3.5% in Q5. Children with a better diet quality (higher quintiles of LLDS) increased significantly less in BMI-z (confounder adjusted βLLDS = -0.064 (-0.101; -0.026)). Children with a poor diet quality at the age of 3 years had a considerably higher risk for overweight at the age of 10 years (confounder adjusted OR for Q1 vs. Q5 was 2.86 (95% CI 1.34-6.13). These results show the importance of diet in healthy development in the early life following the first 1000 days when new habits for a mature diet composed of food groups with lifelong importance are developed, providing a relevant window for overweight prevention early in life.

Adherence to National Food Guide Recommendations: Can It Slow the Obesity Epidemic? A Systematic Review

PURPOSE OF REVIEW

Dietary guidelines (DG) have the objective to promote healthy diet and prevent chronic diseases. In order to evaluate if this purpose is being achieved, we systematically reviewed studies that associated adherence to DG with obesity.

RECENT FINDINGS

We identified 2012 articles published in the last 5 years, and 38 remained in the final sample. The majority of studies demonstrated a negative association between adherence to DG and obesity. Studies with positive or no association presented mutual characteristics, such as populations composed only by children or adolescents, and dietary intake or dietary adherence assessed through non-validated or weak methods. Adherence to DG seems to be a protective factor for obesity in adults, but this relationship is not so clear for children and adolescents. To improve the quality of dietary intake results, studies must utilize appropriate methods to answer their questions with less biased estimate of dietary intake.

Body Mass Index From Early to Late Childhood and Cardiometabolic Measurements at 11 to 12 Years

OBJECTIVES

To examine how overweight and obesity at specific ages and overall BMI growth patterns throughout childhood predict cardiometabolic phenotypes at 11 to 12 years.

METHODS

In a population-based sample of 5107 infants, BMI was measured every 2 years between ages 2 to 3 and 10 to 11 years. We identified 5 BMI trajectories using growth curve models. At ages 11 to 12 years, 1811 children completed assessments for metabolic syndrome risk scores, carotid-femoral pulse wave velocity, and carotid intima-media thickness. Multivariable regression models were used to estimate associations, adjusted for potential confounders (eg, age, sex, smoking exposure, and small for gestational age).

RESULTS

Overweight and obesity from early childhood onward were strongly associated with higher cardiometabolic risk at 11 to 12 years of age. At age 6 to 7 years, compared with those with a healthy weight, children with overweight had higher metabolic syndrome risk scores by 0.23 SD units (95% confidence interval 0.05 to 0.41) and with obesity by 0.76 SD units (0.51-1.01), with associations almost doubling by age 10 to 11 years. Obese (but not overweight) children had higher outcome pulse wave velocity (0.64-0.73 SD units) from ages 6 to 7 years and slightly higher outcome carotid intima-media thickness (0.20-0.30 SD units) at all ages. Cumulative exposure to high BMI from 2 to 3 years of age carried the greatest cardiometabolic risk, with a gradient of risk across trajectories.

CONCLUSIONS

High early-childhood BMI is already silently associated with the development of cardiometabolic risk by 11 to 12 years, highlighting the urgent need for effective action to reduce overweight and obesity in early childhood.