Evaluation of the population-level impacts of the LiveLighter® obesity prevention campaign from 2012 to 2019 based on serial cross-sectional surveys

BACKGROUND

Halting and reversing the upward trend in obesity requires sustained implementation of comprehensive, evidence-based strategies at the population-level. The LiveLighter® program targets adults using a range of public education strategies, including mass media campaigns, to support healthy lifestyle changes to attain or maintain a healthy weight and reduce the risk of chronic disease. LiveLighter® has been implemented in Western Australia (WA) since 2012 and, to our knowledge, includes the longest running adult-targeted mass media campaign for healthy weight and lifestyle promotion and education globally. This evaluation assessed the impact of LiveLighter® on WA adults' knowledge, intentions and behaviours as they relate to healthy eating and body weight from 2012 to 2019.

METHODS

LiveLighter® mass media campaigns, which are TV-led and aired statewide, depict genuine, graphic imagery of visceral fat around internal organs to raise awareness about the link between excess body weight and chronic diseases; demonstrate how unhealthy food and drink consumption can contribute to unhealthy weight gain; and recommend healthy alternatives. Cross-sectional telephone surveys were conducted at baseline and following each campaign phase with an independent, randomly selected sample of WA adults aged 25 to 49 years (n = 501 to n = 1504 per survey) to assess their knowledge of the link between excess body weight and chronic diseases, and their intentions and behaviours related to healthy eating and weight. Multivariable logistic regression models were undertaken to assess differences in responses between baseline and each post-campaign survey.

RESULTS

Compared to baseline, there were significant increases in the proportion of respondents reporting knowledge of excess body weight as a risk factor for certain cancers and type 2 diabetes, intentions to eat more fruit and vegetables and drink less sugar sweetened beverages (SSBs) in the next seven days, and the proportion of respondents who reported meeting guidelines for daily vegetable intake. Reported consumption of SSBs significantly decreased.

CONCLUSIONS

LiveLighter® is associated with improvements in knowledge of the health risks associated with excess body mass, increased vegetable intake and reduced SSB consumption in WA adults. These findings support the use of sustained, well-designed healthy lifestyle promotion and education programs as part of a comprehensive obesity prevention strategy.

Public support for obesity prevention policies in Western Australia from 2012 to 2020: Findings from cross-sectional surveys

ISSUE ADDRESSED

This study explored trends in public support for obesity prevention policies in Western Australia (WA).

METHODS

A series of cross-sectional surveys of a representative sample of WA adults aged 25-49 years (N = 11 534) were undertaken between 2012 and 2020 as part of an evaluation of the LiveLighter® mass media campaign, a component of a statewide healthy lifestyle education and promotion programme. Computer-assisted telephone interviews were used to gauge support for a range of obesity prevention initiatives that could be implemented by government.

RESULTS

A majority of respondents supported a range of obesity prevention policies, including taxes on sugary drinks, urban planning regulations, food labelling and packaging regulations, restrictions on advertising and sponsorship, bans on the sale and marketing of unhealthy food and drink in retail environments and support for education and campaigns. Obesity prevention policies were highly supported by women, people with a healthy weight, and those who had completed secondary school. Support for regulation was high compared to other studies. Notably, there were significant increases in support between baseline and 2020 for 'taxing soft drinks and using the money to reduce the cost of healthy food' (72% cf. 80%) and 'restricting junk food promotions/advertisements on public transport' (73% cf. 83%).

CONCLUSIONS

There is substantial public support for regulatory action on obesity prevention in WA, providing strong rationale for government interventions to improve nutrition and reduce obesity. The LiveLighter® programme may have contributed to increases in support for obesity prevention policies in WA. SO WHAT?: There is potential to implement robust obesity prevention policies in WA.

The community food environment and its association with diet, health or weight status in Australia: A systematic review with recommendations for future research

ISSUE ADDRESSED

This study systematically reviewed Australian literature to determine if an association exists between geospatial exposure to food outlets and diet, health or weight status. Recommendations for future research are provided.

METHODS

A systematic literature search was conducted in December 2021 using CINAHL Plus, PubMed and Web of Science databases. Data were extracted, as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality was assessed using an eight-item checklist. A descriptive synthesis of study characteristics and findings was carried out, stratified via study outcomes.

RESULTS

Of the 36 included articles, the majority were from Victoria (n = 19), involving adult participants (n = 30) and cross-sectional in design (n = 27). Overall, associations were mainly null (nonsignificant) for diet (80%), weight status (75%) and health outcomes (90%). Significant findings were mixed with no positive trend with study quality.

CONCLUSIONS

Six recommendations are suggested to address current knowledge gaps and limitations in the Australian evidence base: (1) Conduct research on different populations; (2) Employ robust study designs that can test the impact of change over time; (3) Improve the accuracy of food outlet data sources; (4) Improve food outlet geospatial exposure measures; (5) Improve measurement of outcome variables; and (6) Incorporate theoretical models into study design and data analysis. SO WHAT?: Improving the quality and consistency of research will be critical to informing locally relevant policy. Despite the present limitations in the evidence base, it is reasonable to assume that decisions to purchase and consume food are driven by availability and access. Thus, policy and planning aimed at improving the overall "healthiness" of the community food environment by increasing access to healthy food outlets is warranted to ensure that healthy options are easier choice for all.

Associations Between Dietary Patterns and Incident Type 2 Diabetes: Prospective Cohort Study of 120,343 UK Biobank Participants

OBJECTIVE

To identify dietary patterns (DPs) characterized by a set of nutrients of concern and their association with incident type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

A total of 120,343 participants from the U.K. Biobank study with at least two 24 h dietary assessments were studied. Reduced rank regression was used to derive DPs explaining variability in energy density, free sugars, saturated fat, and fiber intakes. We investigated prospective associations with T2D using Cox proportional hazard models.

RESULTS

Over 8.4 years of follow-up from the latest dietary assessment, 2,878 participants developed T2D. Two DPs were identified that jointly explained a total of 63% variation in four nutrients. DP1 was characterized by high intakes of chocolate and confectionery, butter, low-fiber bread, and sugars and preserves, and low intakes of fruits and vegetables. DP1 was linearly associated with T2D in multivariable models without BMI adjustment (per z score, hazard ratio [HR] 1.11 [95% CI 1.08-1.14]) and after BMI adjustment (HR 1.09 [95% CI 1.06-1.12]). DP2 was characterized by high intakes of sugar-sweetened beverages, fruit juice, table sugars and preserves, and low intakes of high-fat cheese and butter, but showed no clear association with T2D. There were significant interactions between both DPs and age, with increased risks among younger people in DP1 (HR 1.13 [95% CI 1.09-1.18]) and DP2 (HR 1.10 [95% CI 1.05-1.15]), as well as with DP1 and BMI, with increased risks among people with obesity (HR 1.11 [95% CI 1.07-1.16]).

CONCLUSIONS

A DP characterized by high intakes of chocolate and confectionery, butter, low-fiber bread, and added sugars, and low in fresh fruits and vegetables intake is associated with a higher incidence of T2D, particularly among younger people and those with obesity.

Prospective Associations of Sugar-Sweetened Beverage Consumption During Adolescence with Body Composition and Bone Mass at Early Adulthood

BACKGROUND

Adolescents have a higher consumption of sugar-sweetened beverages (SSBs) than other age groups, but little is known of the impact of SSB intake during adolescence on body composition and bone mass in early adulthood.

OBJECTIVES

Associations of SSB intake from 14 to 20 y with fat, lean, and bone mass at 20 y of age were evaluated.

METHODS

Study participants were 1137 offspring (562 females) from the Raine Study. Food intake, including SSB consumption in servings/d (1 serving = 250 mL), was estimated using FFQs at 14, 17, and 20 y of age. DXA scanning at 20 y measured whole body fat mass, lean mass, and bone mineral content (BMC). Using latent class growth analysis, 4 SSB intake trajectory classes were identified: consistently low (n = 540, intakes mostly <0.5 serving/d), increasing (n = 65), decreasing (n = 258), and consistently high (n = 274, intakes mostly >1.3 servings/d).

RESULTS

Median total SSB intake was 0.8, 0.7, and 0.5 serving/d, and median carbonated SSB intake was 0.3, 0.3, and 0.4 serving/d at 14, 17, and 20 y, respectively. Mean ± SD BMI (in kg/m2) was 23.9 ± 4.2 at 20 y. After adjustment for covariates including sex, demographic, energy intake, and maternal factors, individuals with "consistently high" SSB consumption had significantly higher total body fat mass at 20 y than those with "consistently low" consumption (23.3 ± 0.6 compared with 21.2 ± 0.4 kg, P = 0.004), which remained significant after further adjustment for "Healthy" and "Western" dietary patterns (23.2 ± 0.6 compared with 21.2 ± 0.4 kg, P = 0.011). No significant associations were observed between SSB intake trajectory classes and lean body mass or BMC at 20 y.

CONCLUSIONS

In this cohort, consistently higher consumption of SSBs in adolescence and early adulthood are associated with increased fat mass but not with bone mass at 20 y of age.

Associations between dietary patterns and the incidence of total and fatal cardiovascular disease and all-cause mortality in 116,806 individuals from the UK Biobank: a prospective cohort study

BACKGROUND

Traditionally, studies investigating diet and health associations have focused on single nutrients. However, key nutrients co-exist in many common foods, and studies focusing solely on individual nutrients may obscure their combined effects on cardiovascular disease (CVD) and all-cause mortality. We aimed to identify food-based dietary patterns which operate through excess energy intake and explain high variability in energy density, free sugars, saturated fat, and fiber intakes and to investigate their association with total and fatal CVD and all-cause mortality.

METHODS

Detailed dietary data was collected using a 24-h online dietary assessment on two or more occasions (n = 116,806). We used reduced rank regression to derive dietary patterns explaining the maximum variance. Multivariable Cox-proportional hazards models were used to investigate prospective associations with all-cause mortality and fatal and non-fatal CVD.

RESULTS

Over an average of 4.9 years of follow-up, 4245 cases of total CVD, 838 cases of fatal CVD, and 3629 cases of all-cause mortality occurred. Two dietary patterns were retained that jointly explained 63% of variation in energy density, free sugars, saturated fat, and fiber intakes in total. The main dietary pattern was characterized by high intakes of chocolate and confectionery, butter and low-fiber bread, and low intakes of fresh fruit and vegetables. There was a positive linear association between the dietary pattern and total CVD [hazard ratio (HR) per z-score 1.07, 95% confidence interval (CI) 1.04-1.09; HRtotal CVD 1.40, 95% CI 1.31-1.50, and HRall-cause mortality 1.37, 95% CI 1.27-1.47 in highest quintile]. A second dietary pattern was characterized by a higher intakes of sugar-sweetened beverages, fruit juice, and table sugar/preserves. There was a non-linear association with total CVD risk and all-cause mortality, with increased risk in the highest quintile [HRtotal CVD 1.14, 95% CI 1.07-1.22; HRall-cause mortality 1.11, 95% CI 1.03-1.19].

CONCLUSIONS

We identified dietary patterns which are associated with increased risk of CVD and all-cause mortality. These results help identify specific foods and beverages which are major contributors to unhealthy dietary patterns and provide evidence to underpin food-based dietary advice to reduce health risks.

Do Changes in the Local Food Environment Within New Residential Developments Influence the Diets of Residents? Longitudinal Results from RESIDE

Background: There is limited longitudinal evidence supporting a link between food outlet locations and dietary outcomes to inform policy and urban planning. This study examined how longitudinal changes in the local food environment within new residential developments influenced changes in adult dietary intake. Methods: Adult participant data (n = 3223 person-observations) were sourced from the RESIDential Environments (RESIDE) project across three time points between 2004 to 2012 in Perth, Western Australia. Fixed effects regression estimated the relationship between change in spatial exposure to the local food environment, individual behaviours and perceptions of the local food environment with dietary outcome variables (healthy diet score, unhealthy diet score, diet quality score and fruit/vegetable intake). Results: An increase over time in the percentage of healthy food outlets around the home was significantly (p ≤ 0.05) associated with an increase in healthy diet scores and an increase in the distance from home to the nearest café restaurant was significantly (p ≤ 0.05) associated with an increase in diet quality scores. Conclusions: Modifying the local food environment by increasing the relative proportion of healthy food outlets around the home may support healthier dietary intake.

Associations between major dietary patterns and testicular function in a population-based cohort of young men: results from the Western Australian Pregnancy Cohort (Raine) Study

BACKGROUND

Controversial speculation suggestions that dietary intake may affect semen quality and testicular function, however, there are limited comprehensive studies observing dietary patterns.

OBJECTIVE

To study associations between major dietary patterns and markers of testicular function in adulthood.

MATERIAL AND METHODS

Observational cross-sectional study of two hundred and ninety men with an average age of 20 years, from the Western Australian Pregnancy Cohort (Raine) Study. Usual dietary intake assessed using a semi-quantitative food frequency questionnaire at 20 years of age. Two dietary patterns previously identified using exploratory factor analysis ("Healthy" or "Western") and participants received z-scores for each dietary pattern. Primary endpoints were testicular volume, total sperm per ejaculate, morning serum testosterone concentration. Secondary endpoints were semen sample parameters, inhibin B and sex steroids (DHT: 3α-diol, 3β-diol; LH; FSH; DHEA; estradiol; estrone).

RESULT(S)

Participants were on average 20.0 ± 0.4 years old, had a median of 2 days sexual abstinence and a body mass index of 24.1 ± 3.9 kg/m² , 13% were smokers, 52% were 'moderate' alcohol drinkers, 23% frequently used recreational drugs and 68% reported 'high' physical activity levels. Sperm concentration and DHT 3α-diol were negatively associated with a greater z-score for the "Western" dietary pattern (p = 0.007 and; p = 0.044, respectively), and serum estradiol concentration was positively associated with a "Western" dietary pattern (p = 0.007) after adjustment for BMI, varicocele, cryptorchidism and sexual abstinence.

DISCUSSION

Despite associations between greater intake of the "Western" dietary pattern and a decreased male reproductive health markers, our lack of consistent associations of either a "Healthy" or a "Western" dietary pattern, limit clinical or biological significance in isolation.

CONCLUSIONS

A potential negative association of a "Western" dietary pattern with male reproductive health was detected and should be studied further in population-based studies.

Greater improvements in diet quality among overweight participants following a group-based commercial weight loss programme than those receiving support to lose weight in primary care

BACKGROUND

Relatively little is known about dietary changes and their relationships with weight change during behavioural weight loss interventions. In a secondary analysis of data from a multicentre RCT, we investigated whether greater improvements in diet would be achieved by overweight adults following a 12 month group-based commercial weight loss programme (CP) than those receiving standard care (SC) in primary practice, and if these dietary changes were associated with greater weight loss.

METHODS

Adults with a BMI 27-35 kg/m2 and >1 risk factor for obesity-related disorders were recruited in study centres in Australia and the UK during 2007-2008. Dietary intake and body weight were measured at baseline, 6 and 12 months. Linear mixed effects models compared mean changes in dietary macronutrient intake, fibre density and energy density over time between groups, and their relationships with weight loss.

RESULTS

The CP group demonstrated greater mean weight loss than the SC group at 6 months (3.3 kg, 95% CI: 2.2, 4.4) and 12 months (3.3 kg, 95% CI: 2.1, 4.5). Diet quality improved in both intervention groups at 6 and 12 months. However, the CP group (n = 228) achieved significantly greater mean reductions in energy intake (mean difference; 95% CI: - 503 kJ/d; - 913, - 93), dietary energy density (- 0.48 MJ/g; - 0.81, - 0.16), total fat (- 6.9 g/d; - 11.9, - 1.8), saturated fat (- 3.3 g/d; - 5.4, - 1.1), and significantly greater mean increases in fibre density (0.30 g/MJ; 0.15, 0.44) at 6 months than the SC group (n = 239). Similar differences persisted at 12 months and the CP group showed greater mean increases in protein density (0.65 g/MJ). In both groups, weight loss was associated with increased fibre density (0.68 kg per g/MJ, 95% CI: 0.08, 1.27) and protein density (0.26 kg per g/MJ, 95% CI: 0.10, 0.41).

CONCLUSIONS

Following a group-based commercial program led to greater improvements in diet quality than standard care. Increases in dietary protein and fibre density were independently associated with weight loss in both behavioural weight loss interventions. Greater increases in protein and fibre density in the commercial program likely contributed to their greater weight loss.

TRIAL REGISTRATION

ISRCTN: ISRCTN85485463 Registered 03/08/2007 Retrospectively Registered.

A dietary pattern derived using B-vitamins and its relationship with vascular markers over the life course

Background

Diet may influence vascular function through elevated homocysteine (Hcy) concentrations. However the relationship between dietary patterns (DP), characterised by Hcy and its associated nutrients is unknown.

Objective

To identify a DP characterised by plasma Hcy, dietary folate and dietary vitamin B12, and examine its associations with two markers of vascular function: carotid intima-media thickness (cIMT) and pulse wave velocity (PWV).

Methods

1562 participants of the MRC National Survey of Health and Development (NSHD), a British birth cohort, with dietary data measured at least once between 36 and 60–64 years, and cIMT or PWV measured at 60–64 years were included. DPs were derived using reduced rank regression with three intermediate variables: 1) plasma Hcy (μmol/L) 2) folate intake (μg/1000 kcal) 3) vitamin B12 intake (μg/1000 kcal). Multiple regression models assessed associations between the derived DP z-scores and vascular function adjusting for dietary misreporting, socioeconomic position, BMI, smoking, physical activity and diabetes.

Results

A DP explaining the highest amount of shared variation (4.5%) in plasma Hcy, dietary folate and dietary vitamin B12 highly correlated with folate (r = 0.96), moderately correlated with vitamin B12 (r = 0.27), and weakly correlated with Hcy (r = 0.10). This “high B-vitamin” DP (including folate) was characterised by high intakes of vegetables, fruit and low fibre breakfast cereal, and low intakes of processed meat, white bread, sugar and preserves. No associations were observed between DP z-scores and vascular function at any time point following adjustment for covariates.

Conclusion

This study explored a specific hypothesised pathway linking diet to vascular function. Although we found no consistent evidence for an association between a high B-vitamin DP and vascular function, we did observe an association with CRP and triglycerides in secondary analyses. Further analyses using strongly correlated and biologically relevant intermediate variables are required to refine investigations into diet and CVD in longitudinal cohort data.

Unhealthy Dietary Patterns Established in Infancy Track to Mid-Childhood: The EU Childhood Obesity Project

Background

Dietary habits established in infancy may persist into adulthood and determine long-term health.

Objectives

The aims of this work were to describe dietary patterns, predictors of adherence to them, and their tracking from ages 1 to 8 y in European children.

Methods

Three-day food diaries were prospectively collected at ages 1, 2, 3, 4, 5, 6 and 8 y. Foods were allocated to 1 of 29 food groups, which were included in exploratory factor analyses at each children's age. The tracking of patterns through childhood was assessed by an estimated general equation model.

Results

At age 1 y (n = 633), 2 patterns were identified. One was labeled "core foods" (CORE), since it was positively loaded for vegetables, fish, olive oil, and white and red meat, and negatively loaded for ready-to-eat infant products, sugar, and confectioneries. The other was positively loaded for saturated spreads, sugar, fruit juices, and confectioneries, and negatively loaded for olive oil, fish, and cow milk; this was labeled as the "poor-quality fats and added sugars" (F&S) pattern. From ages 2 to 8 y, 3 patterns were repeatedly identified: CORE, F&S, and a "high protein sources" (PROT) pattern that was positively loaded for milk, flavored milks, fish, eggs, white and processed meat, chips, and olive oil, and negatively loaded for fresh fruits at almost all time points. Of those children in the highest quartiles of the CORE, F&S, and PROT patterns at 2 y, 45%, 72%, and 36%, respectively, remained in the highest quartile at 8 y [OR = 2.01 (1.08, 3.8), OR = 3.6 (1.5, 8.4) and OR = 0.80 (0.4,1.6), respectively; P = 0.510].

Conclusions

Dietary patterns are established between 1 and 2 y of age and track into mid-childhood. A dietary pattern characterized by added sugars, unhealthy fats, and poor consumption of fish and olive oil was the most stable throughout childhood. Further analyses will reveal whether those dietary patterns are associated with metabolic disease risk.

Can a Simple Dietary Index Derived from a Sub-Set of Questionnaire Items Assess Diet Quality in a Sample of Australian Adults?

Large, longitudinal surveys often lack consistent dietary data, limiting the use of existing tools and methods that are available to measure diet quality. This study describes a method that was used to develop a simple index for ranking individuals according to their diet quality in a longitudinal study. The RESIDential Environments (RESIDE) project (2004-2011) collected dietary data in varying detail, across four time points. The most detailed dietary data were collected using a 24-item questionnaire at the final time point (n = 555; age ≥ 25 years). At preceding time points, sub-sets of the 24 items were collected. A RESIDE dietary guideline index (RDGI) that was based on the 24-items was developed to assess diet quality in relation to the Australian Dietary Guidelines. The RDGI scores were regressed on the longitudinal sub-sets of six and nine questionnaire items at T4, from which two simple index scores (S-RDGI1 and S-RDGI2) were predicted. The S-RDGI1 and S-RDGI2 showed reasonable agreement with the RDGI (Spearman's rho = 0.78 and 0.84; gross misclassification = 1.8%; correct classification = 64.9% and 69.7%; and, Cohen's weighted kappa = 0.58 and 0.64, respectively). For all of the indices, higher diet quality was associated with being female, undertaking moderate to high amounts of physical activity, not smoking, and self-reported health. The S-RDGI1 and S-RDGI2 explained 62% and 73% of the variation in RDGI scores, demonstrating that a large proportion of the variability in diet quality scores can be captured using a relatively small sub-set of questionnaire items. The methods described in this study can be applied elsewhere, in situations where limited dietary data are available, to generate a sample-specific score for ranking individuals according to diet quality.

Feasibility of a commercial smartphone application for dietary assessment in epidemiological research and comparison with 24-h dietary recalls

Background

Dietary assessment methods that can provide high quality data while limiting participant burden and resource requirements in epidemiological research are highly sought after and continue to evolve. The use of mobile phone technology in research has increased rapidly over the last decade and offers multiple advantages to the researcher over traditional data collection methods. This study tested the acceptability and relative validity of a commercial smart phone application (app) for use as an epidemiological dietary assessment tool, compared with a traditional dietary assessment method.

Methods

Study participants completed a 4-d food diary using a modified version of the Easy Diet Diary app and two 24-h dietary recalls during the same week, for comparison. At the end of data collection, participants completed a questionnaire on their experience with both methods. Average proportions of energy from macronutrients and fibre, iron, and calcium densities from the app and 24-h recalls were compared after log transformation, by calculating mean agreement, limits of agreement (LOA), and Pearson’s correlations. The prevalence of dietary under-reporting was compared in each method using the Goldberg method.

Results

A total of 50 adults (82% women) provided data for analysis (mean age, 31 y; mean BMI, 22.4 kg/m²; 14% overweight or obese). Participant feedback showed high levels of acceptance of the app; 83% preferred using the app to completing 24-h dietary recalls. The average difference in energy intake (mean agreement) between methods was 268 kJ/d. For all intakes except alcohol, the average difference between methods was not significantly different from zero. Most limits of agreement were within an acceptable range. The prevalence of dietary misreporting was similar in both methods.

Conclusions

These findings demonstrate good feasibility for applying this commercially-developed smartphone app in epidemiological research.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0315-4) contains supplementary material, which is available to authorized users.

Determinants of a dietary pattern linked with greater metabolic risk and its tracking during adolescence

BACKGROUND

Although growing evidence suggests that dietary patterns associated with noncommunicable diseases in adulthood may develop early in life, when these are established, as well as their determinants, remains unclear.

METHODS

We examined determinants and tracking of a dietary pattern (DP) associated with metabolic risk and its key food groups among 860 adolescents in the Western Australian Pregnancy (Raine) Cohort study. Food intake was reported using a food frequency questionnaire (FFQ) at 14 and 17 years. Z-scores for an 'energy-dense, high-fat, low-fibre' DP were estimated by applying reduced rank regression at both ages. Tracking was based on the predictive value (PV) of remaining in the DPZ-score or food intake quartile at 14 and 17 years. Early-life exposures included: maternal age; maternal pre-pregnancy body mass index; parent smoking status during pregnancy; and parent socio-economic position (SEP) at 14 and 17 years. Associations between the DPZ-scores, early-life factors and SEP were analysed using regression analysis.

RESULTS

Dietary tracking was strongest among boys with high DPZ-scores, high intakes of processed meat, low-fibre bread, crisps and savoury snacks (PV > 1) and the lowest intakes of vegetables, fruit and legumes. Lower maternal education (β = 0.09, P = 0.002 at 14 years; β = 0.14, P < 0.001 at 17 years) and lower maternal age at birth (β = 0.09, P = 0.003 at 14 years; β = 0.11, P = 0.004 at 17 years) were positively associated with higher DPZ-scores.

CONCLUSIONS

An energy-dense, high-fat, low-fibre dietary pattern tracks more strongly among adolescent boys who have high scores for this pattern at 14 years of age. These findings highlight target foods and population subgroups for early interventions aiming to improve dietary behaviours.

Changes in diet from age 10 to 14 years and prospective associations with school lunch choice

BACKGROUND

There is limited evidence on how diet changes over the transition from primary to secondary school. In this study we investigated changes in diet from age 10 (2007) to age 14 years (2011) and the contribution of school-time consumption and school lunch choice to such changes.

METHODS

The 351 participants with dietary data (4 day food record) available at baseline (age 10 years) and follow-up (age 14 years) were included. Multi-level regression models were fitted for absolute or change in food and nutrient intake, cross-classified by primary and secondary school attended as appropriate, with adjustment for covariates and mis-reporting.

RESULTS

From age 10 to age 14 years, children decreased energy intake from sugars (-2.6% energy (%E)) (standard error (SE) 0.44) and from saturated fats (-0.54%E (SE 0.18)), decreased fruit (-3.13 g/MJ (SE 1.04)) and vegetables (-1.55 g/MJ (SE 0.46)) consumption and increased sugar sweetened beverage (SSB) (4.66  g/MJ (SE 1.87)) and fries (1.31  g/MJ (SE 0.39)) consumption. Intake of snack foods, SSBs, and fries, but also fruits and vegetables was higher outside school hours. Prospective change from non-school lunch to school lunch, compared to maintaining non-school lunch consumption, was associated with decreased consumption of savoury snacks (-8.32 g/day (SE 2.03)), increased consumption of fries (12.8 g/day (SE 4.01)) and decreased consumption of fruit (-25.16 g/day (SE 11.02)) during school hours.

CONCLUSIONS

Changes in diet from age 10 to age 14 years differed within and outside of school hours. Consumption of a school lunch, compared to lunch obtained elsewhere, was associated with negative as well as positive changes in diet, suggesting that any efforts to encourage school lunch take-up need to be accompanied by further efforts to improve school lunch provision to meet nutritional guidelines.

Life Course Dietary Patterns and Bone Health in Later Life in a British Birth Cohort Study

Evidence for the contribution of individual foods and nutrients to bone health is weak. Few studies have considered hypothesis-based dietary patterns and bone health. We investigated whether a protein-calcium-potassium-rich (PrCaK-rich) dietary pattern over the adult life course, was positively associated with bone outcomes at 60 to 64 years of age. Diet diaries were collected at ages 36, 46, 53, and 60 to 64 years in 1263 participants (661 women) from the MRC National Survey of Health and Development. DXA and pQCT measurements were obtained at age 60 to 64 years, including size-adjusted bone mineral content (SA-BMC) and volumetric bone mineral density (vBMD). A food-based dietary pattern best explaining dietary calcium, potassium, and protein intakes (g/1000 kcal) was identified using reduced rank regression. Dietary pattern Z-scores were calculated for each individual, at each time point. Individual trajectories in dietary pattern Z-scores were modeled to summarize changes in Z-scores over the study period. Regression models examined associations between these trajectories and bone outcomes at age 60 to 64 years, adjusting for baseline dietary pattern Z-score and other confounders. A consistent PrCaK-rich dietary pattern was identified within the population, over time. Mean ± SD dietary pattern Z-scores at age 36 years and age 60 to 64 years were -0.32 ± 0.97 and 2.2 ± 1.5 (women) and -0.35 ± 0.98 and 1.7 ± 1.6 (men), respectively. Mean trajectory in dietary pattern Z-scores ± SD was 0.07 ± 0.02 units/year. Among women, a 0.02-SD unit/year higher trajectory in dietary pattern Z-score over time was associated with higher SA-BMC (spine 1.40% [95% CI, 0.30 to 2.51]; hip 1.35% [95% CI, 0.48 to 2.23]), and vBMD (radius 1.81% [95% CI, 0.13 to 3.50]) at age 60 to 64 years. No statistically significant associations were found in men. During adulthood, an increasing score for a dietary pattern rich in protein, calcium, and potassium was associated with greater SA-BMC at fracture-prone sites in women. This study emphasizes the importance of these nutrients, within the context of the whole diet, to bone health. © 2016 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).

Free Sugars and Total Fat Are Important Characteristics of a Dietary Pattern Associated with Adiposity across Childhood and Adolescence

BACKGROUND

The importance of dietary sugar compared with fat in the development of obesity is currently a topic of debate.

OBJECTIVE

We aimed to identify dietary patterns (DPs) characterized by high sugar content, high fat content, or both and their longitudinal associations with adiposity during childhood and adolescence.

METHODS

Participants were 6722 children from the ALSPAC (Avon Longitudinal Study of Parents and Children) who were born in 1991-1992. DPs were characterized by percentage of total energy intake (%E) from free sugars, %E from total fat, and dietary energy density (DED) and fiber density by using reduced rank regression at 7, 10, and 13 y of age. Total body fat mass was measured at 11, 13, and 15 y of age. Regression analyses were used to adjust for dietary misreporting, physical activity, and maternal social class.

RESULTS

Two major DPs were identified: higher z scores for DP1 were associated with greater DED, greater %E from free sugars and total fat, and lower fiber density; higher z scores for DP2 were associated with greater %E from free sugars but lower %E from total fat and DED. A 1-SD increase in z score for DP1 was associated with a mean increase in the fat mass index z score of 0.04 SD units (95% CI: 0.01, 0.07; P = 0.017) and greater odds of excess adiposity (OR: 1.12; 95% CI: 1.0, 1.25; P = 0.038). DP2 was not associated with adiposity.

CONCLUSIONS

An energy-dense DP high in %E from total fat and free sugars is associated with greater adiposity in childhood and adolescence. This appears to confirm the role of both fat and sugar and provides a basis for food-based dietary guidelines to prevent obesity in children.

A prospective investigation of dietary patterns and internalizing and externalizing mental health problems in adolescents

Investigating protective and risk factors that influence mental health in young people is a high priority. While previous cross-sectional studies have reported associations between diet and mental health among adolescents, few prospective studies exist. The aim of this study was to examine prospective relationships between dietary patterns and mental health among adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study. Self-report questionnaires were used to assess indicators of mental health (Youth Self-Report externalizing/internalizing T-scores) and Western and Healthy dietary patterns (identified using factor analysis) at 14 (2003-2005) and 17 years (2006-2008). Multivariate linear and logistic regression were used to assess relationships between dietary patterns and mental health. Complete data were available for 746 adolescents. In females only, the Western dietary pattern z-score at 14 years was positively associated with greater externalizing behaviors at 17 years (β = 1.91; 95% CI: 0.04, 3.78) and a greater odds of having clinically concerning externalizing behaviors at 17 years (OR = 1.90; 95% CI: 1.06, 3.41). No other statistically significant associations were observed. Overall our findings only lend partial support to a link between diet and mental health. We found it to be specific to females consuming a Western dietary pattern and to externalizing behaviors. Future research on dietary patterns and mental health needs to consider possible sex differences and distinguish between different mental health outcomes as well as between healthy and unhealthy dietary patterns.

Dietary protein intake is associated with body mass index and weight up to 5 y of age in a prospective cohort of twins

BACKGROUND

Few large epidemiologic studies have investigated the role of postweaning protein intake in excess weight and adiposity of young children, despite children in the United Kingdom consistently consuming protein in excess of their physiologic requirements.

OBJECTIVE

We investigated whether a higher proportion of protein intake from energy beyond weaning is associated with greater weight gain, higher body mass index (BMI), and risk of overweight or obesity in children up to 5 y of age.

DESIGN

Participants were 2154 twins from the Gemini cohort. Dietary intake was collected by using a 3-d diet diary when the children had a mean age of 21 mo. Weight and height were collected every 3 mo, from birth to 5 y. Longitudinal models investigated associations of protein intake with BMI, weight, and height, with adjustment for age at diet diary, sex, total energy intake, birth weight/length, and rate of prior growth and clustering within families. Logistic regression investigated protein intake in relation to the odds of overweight or obesity at 3 and 5 y of age.

RESULTS

A total of 2154 children had a mean ± SD of 5.7 ± 3.2 weight and height measurements up to 5 y. Total energy from protein was associated with higher BMI (β = 0.043; 95% CI: 0.011, 0.075) and weight (β = 0.052; 95% CI: 0.031, 0.074) but not height (β = 0.088; 95% CI: -0.038, 0.213) between 21 mo and 5 y. Substituting percentage energy from fat or carbohydrate for percentage energy from protein was associated with decreases in BMI and weight. Protein intake was associated with a trend in increased odds of overweight or obesity at 3 y (OR = 1.10; 95% CI 0.99, 1.22, P = 0.075), but the effect was not statistically significant at 5 y.

CONCLUSION

A higher proportion of energy from protein during the complementary feeding stage is associated with greater increases in weight and BMI in early childhood in this large cohort of United Kingdom children.

Regular Fat and Reduced Fat Dairy Products Show Similar Associations with Markers of Adolescent Cardiometabolic Health

Reduced fat dairy products are generally recommended for adults and children over the age of two years. However, emerging evidence suggests that dairy fat may not have detrimental health effects. We aimed to investigate prospective associations between consumption of regular versus reduced fat dairy products and cardiometabolic risk factors from early to late adolescence. In the West Australian Raine Study, dairy intake was assessed using semi-quantitative food frequency questionnaires in 860 adolescents at 14 and 17-year follow-ups; 582 of these also had blood biochemistry at both points. Using generalized estimating equations, we examined associations with cardiometabolic risk factors. Models incorporated reduced fat and regular fat dairy together (in serves/day) and were adjusted for a range of factors including overall dietary pattern. In boys, there was a mean reduction in diastolic blood pressure of 0.66 mmHg (95% CI 0.23–1.09) per serve of reduced fat dairy and an independent, additional reduction of 0.47 mmHg (95% CI 0.04–0.90) per serve of regular fat dairy. Each additional serve of reduced fat dairy was associated with a 2% reduction in HDL-cholesterol (95% CI 0.97–0.995) and a 2% increase in total: HDL-cholesterol ratio (95% CI 1.002–1.03); these associations were not observed with regular fat products. In girls, there were no significant independent associations observed in fully adjusted models. Although regular fat dairy was associated with a slightly better cholesterol profile in boys, overall, intakes of both regular fat and reduced fat dairy products were associated with similar cardiometabolic associations in adolescents.

How often should general practitioners provide nutrition care to patients? A forecasting activity to determine the target frequency for chronic-disease management in Australia

Supporting patients to have healthy dietary behaviours contributes significantly to preventing and managing lifestyle-related chronic diseases. ‘Nutrition care’ refers to any practice provided by a health professional to support a patient to improve their dietary behaviours and subsequent health outcomes. Approximately 3% of consultations by Australian general practitioners (GPs) involve the provision of nutrition care. The aim of the present paper was to forecast the potential implications of a higher frequency of nutrition care by GPs. Evidence on the effect of improved dietary behaviours on chronic disease outcomes, number of Australian adults estimated to have poor dietary behaviours and effectiveness of GPs providing nutrition care were taken into consideration. Using hypertension as a case example, for GPs to provide nutrition care to all hypertensive adults who would benefit from improved dietary behaviours, GPs would need to provide nutrition care in a target rate of 4.85% of consultations or 4.5 million different patients each year. The target aligns with the existing priorities for supporting chronic-disease prevention and management in Australia by increasing the rate that brief lifestyle interventions are provided by primary health professionals. This conservative target presents a considerable challenge for GPs, support staff, researchers and policy makers, but can be used to inform future interventions to support nutrition care by GPs.

Identification of a dietary pattern prospectively associated with bone mass in Australian young adults

BACKGROUND

Relatively little is known about the relations between dietary patterns and bone health in adolescence, which is a period of substantial bone mass accrual.

OBJECTIVES

We derived dietary patterns that were hypothesized to be related to bone health on the basis of their protein, calcium, and potassium contents and investigated their prospective associations with bone mineral density (BMD), bone area, and bone mineral content (BMC) in a cohort of young adults.

DESIGN

The study included 1024 young adults born to mothers who were participating in the Western Australian Pregnancy Cohort (Raine) Study. Dietary information was obtained from food-frequency questionnaires at 14 and 17 y of age. Dietary patterns were characterized according to protein, calcium, and potassium intakes with the use of reduced-rank regression. BMD, bone area, and BMC were estimated with the use of a total body dual-energy X-ray absorptiometry scan at 20 y of age.

RESULTS

We identified 2 major dietary patterns. The first pattern was positively correlated with intakes of protein, calcium, and potassium and had high factor loadings for low-fat dairy products, whole grains, and vegetables. The second pattern was positively correlated with protein intake but negatively correlated with intakes of calcium and potassium and had high factor loadings for meat, poultry, fish, and eggs. After adjustment for anthropometric, sociodemographic, and lifestyle factors, a higher z score for the first pattern at 14 y of age was positively associated with BMD and BMC at 20 y of age [differences: 8.6 mg/cm(2) (95% CI: 3.0, 14.1 mg/cm(2)) and 21.9 g (95% CI: 6.5, 37.3 g), respectively, per SD increase in z score]. The z score for this same pattern at 17 y of age was not associated with bone outcomes at 20 y of age. The second pattern at 14 or 17 y of age was not associated with BMD, BMC, or bone area.

CONCLUSIONS

A dietary pattern characterized by high intakes of protein, calcium, and potassium in midadolescence was associated with higher BMD and BMC at 20 y of age. Our results indicate that high consumption of low-fat dairy products, whole grains, and vegetables in adolescence are associated with beneficial effects on bone development.

Modelling the Interplay between Lifestyle Factors and Genetic Predisposition on Markers of Type 2 Diabetes Mellitus Risk

The risk of developing type 2 diabetes mellitus (T2DM) is determined by a complex interplay involving lifestyle factors and genetic predisposition. Despite this, many studies do not consider the relative contributions of this complex array of factors to identify relationships which are important in progression or prevention of complex diseases. We aimed to describe the integrated effect of a number of lifestyle changes (weight, diet and physical activity) in the context of genetic susceptibility, on changes in glycaemic traits in overweight or obese participants following 12-months of a weight management programme. A sample of 353 participants from a behavioural weight management intervention were included in this study. A graphical Markov model was used to describe the impact of the intervention, by dividing the effects into various pathways comprising changes in proportion of dietary saturated fat, physical activity and weight loss, and a genetic predisposition score (T2DM-GPS), on changes in insulin sensitivity (HOMA-IR), insulin secretion (HOMA-B) and short and long term glycaemia (glucose and HbA1c). We demonstrated the use of graphical Markov modelling to identify the importance and interrelationships of a number of possible variables changed as a result of a lifestyle intervention, whilst considering fixed factors such as genetic predisposition, on changes in traits. Paths which led to weight loss and change in dietary saturated fat were important factors in the change of all glycaemic traits, whereas the T2DM-GPS only made a significant direct contribution to changes in HOMA-IR and plasma glucose after considering the effects of lifestyle factors. This analysis shows that modifiable factors relating to body weight, diet, and physical activity are more likely to impact on glycaemic traits than genetic predisposition during a behavioural intervention.

Identification of a dietary pattern associated with greater cardiometabolic risk in adolescence

BACKGROUND AND AIMS

Energy dense, high fat, low fibre diets may contribute to obesity in young people, however their relationships with other cardiometabolic risk factors are unclear. We examined associations between an 'energy-dense, high-fat and low-fibre' dietary pattern (DP) and cardiometabolic risk factors, and the tracking of this DP in adolescence.

METHODS AND RESULTS

Data was sourced from participants in the Western Australian Pregnancy (Raine) Cohort Study. At 14 and 17 y, dietary intake, anthropometric and biochemical data were measured and z-scores for an 'energy dense, high fat and low fibre' DP were estimated using reduced rank regression (RRR). Associations between DP z-scores and cardiometabolic risk factors were examined using regression models. Tracking of DP z-scores was assessed using Pearson's correlation coefficient. A 1 SD unit increase in DP z-score between 14 and 17 y was associated with a 20% greater odds of high metabolic risk (95% CI: 1.01, 1.41) and a 0.04 mmol/L higher fasting glucose in boys (95% CI: 0.01, 0.08); a 28% greater odds of a high-waist circumference (95% CI: 1.00, 1.63) in girls. An increase of 3% and 4% was observed for insulin and HOMA (95% CI: 1%, 7%), respectively, in boys and girls, for every 1 SD increase in DP z-score and independently of BMI. The DP showed moderate tracking between 14 and 17 y of age (r = 0.51 for boys, r = 0.45 for girls).

CONCLUSION

An 'energy dense, high fat, low fibre' DP is positively associated with cardiometabolic risk factors and tends to persist throughout adolescence.

Dietary patterns, cardiometabolic risk factors, and the incidence of cardiovascular disease in severe obesity

OBJECTIVE

The longitudinal associations between a dietary pattern (DP) and cardiometabolic risk factors and cardiovascular disease (CVD) incidence were investigated in a cohort of adults with severe obesity.

METHODS

The analysis included 2,037 individuals with severe obesity (>34 and >38 kg/m(2) for men and women, respectively) from the Swedish Obese Subjects study repeatedly followed up for 10 years. Reduced rank regression was used to identify a DP characterized by dietary energy density, saturated fat intake, and fiber density. Mixed models examined relationships between repeated measures of DP z-scores and cardiometabolic risk factors. Cox proportional hazards models assessed relationships between DP scores and CVD incidence.

RESULTS

An energy-dense, high-saturated-fat, and low-fiber DP was derived. A one-unit increase in the DP z-score between follow-ups was associated with an increase in weight [β (SE)] (1.71 ± 0.10 kg), waist circumference (1.49 ± 0.07 cm), BMI (0.60 ± 0.34 kg/m2), serum cholesterol (0.06 ± 0.01 mmol/l), and serum insulin (1.22 ± 0.17 mmol/l; all P < 0.0001), as well as in serum triglycerides (0.05 ± 0.02 mmol/l; P < 0.05), systolic blood pressure (1.05 ± 0.27 mmHg; P < 0.001), and diastolic blood pressure (0.55 ± 0.16 mmHg; P < 0.05). No significant association was observed between repeated measures of the DP z-scores and CVD incidence (HR = 0.96; 95% CI = 0.83-1.12).

CONCLUSIONS

An energy-dense, high-saturated-fat, and low-fiber DP was longitudinally associated with increases in cardiometabolic risk factors in severe obesity but not with CVD incidence.

Prospective associations between dietary patterns and cognitive performance during adolescence

BACKGROUND

The aim of the study was to investigate prospective associations between dietary patterns and cognitive performance during adolescence.

METHODS

Participants were sourced from the Western Australian Pregnancy Cohort (Raine) Study that includes 2868 children born between 1989 and 1992 in Perth, Western Australia. When the children were 17 years old (2006-2009), cognitive performance was assessed using a computerized cognitive battery of tests (CogState) that included six tasks. Using a food frequency questionnaire administered when the children were 14 years old (2003-2006), 'Healthy' and 'Western' dietary patterns were identified by factor analysis. Associations between dietary patterns at 14 years of age and cognitive performance at 17 years of age were assessed prospectively using multivariate regression models.

RESULTS

Dietary and cognitive performance data were available for 602 participants. Following adjustment for the 'Healthy' dietary pattern, total energy intake, maternal education, family income, father's presence in the family, family functioning and gender, we found that a longer reaction time in the detection task (β = .016; 95% CI: 0.004; 0.028; p = .009) and a higher number of total errors in the Groton Maze Learning Test - delayed recall task (β = .060; 95% CI: 0.006; 0.114; p = .029) were significantly associated with higher scores on the 'Western' dietary pattern. The 'Western' dietary pattern was characterized by high intakes of take-away food, red and processed meat, soft drink, fried and refined food. We also found that within the dietary patterns, high intake of fried potato, crisps and red meat had negative associations, while increased fruit and leafy green vegetable intake had positive associations with some aspects of cognitive performance.

CONCLUSION

Higher dietary intake of the 'Western' dietary pattern at age 14 is associated with diminished cognitive performance 3 years later, at 17 years.

Tracking of a dietary pattern and its components over 10-years in the severely obese

Understanding how dietary intake changes over time is important for studies of diet and disease and may inform interventions to improve dietary intakes. We investigated how a dietary pattern (DP) tracked over 10-years in the Swedish Obese Subjects (SOS) study control group. Dietary intake was assessed at multiple time-points in 2037 severely obese individuals (BMI 41 ± 4 kg/m(2)). Reduced rank regression was used to derive a dietary pattern using dietary energy density (kJ/g), saturated fat (%) and fibre density (mg/kJ) as response variables and score respondents at each follow-up. Tracking coefficients for the DP, its key foods and macronutrient response variables and corrected for time-dependent and time-independent covariates were calculated using generalised estimating equations to take into account all available data. The DP tracking coefficient was moderate for women (0.40; 95% CI: 0.38-0.42) and men (0.38; 95% CI: 0.35-0.41). Of the eleven foods key to this DP, fruit and vegetable intakes had the strongest tracking coefficient for both sexes. Fast food and candy had the lowest tracking coefficients for women and men respectively. Scores for an energy dense, high saturated fat, low fibre density DP appear moderately stable over a 10-year period in this severely obese population. Furthermore, some food groups appear more amenable to change while others, often the most healthful, appear more stable and may require intervention before adulthood.

Tracking a dietary pattern associated with increased adiposity in childhood and adolescence

OBJECTIVE

Understanding dietary tracking may help to inform interventions to improve dietary intakes and health outcomes. This study investigated how a dietary pattern (DP) associated with increased adiposity in childhood tracked from 7 to 13 years of age, in the Avon Longitudinal Study of Parents and Children (ALSPAC).

DESIGN AND METHODS

Three-day food diaries were collected at 7, 10 and 13 years. Reduced rank regression was used to score respondents for an energy-dense, high fat, low fiber DP at each age. Tracking coefficients were estimated for the DP and its key foods using data from 7,027 children.

RESULTS

The DP tracking coefficient was 0.48 (95% CI: 0.44-0.52) for boys and 0.38 (95% CI: 0.35-0.41) for girls. Of 10 key food groups, fruit, vegetables, high fiber bread, high fiber breakfast cereals and full fat milk intakes exhibited the strongest tracking, particularly among low consumers. Lower maternal education and greater prepregnancy maternal BMI predicted higher DP z scores and lower fruit and vegetable intakes.

CONCLUSIONS

A dietary pattern associated with increased adiposity tracks moderately from 7 to 13 years of age in this large UK cohort. Specific groups of families may require additional support to foster lifelong healthy dietary habits in their children.

Dietary energy intake is associated with type 2 diabetes risk markers in children

OBJECTIVE Energy intake, energy density, and nutrient intakes are implicated in type 2 diabetes risk in adults, but little is known about their influence on emerging type 2 diabetes risk in childhood. We examined these associations in a multiethnic population of children. RESEARCH DESIGN AND METHODS This was a cross-sectional study of 2,017 children predominantly of white European, South Asian, and black African-Caribbean origin aged 9-10 years who had a detailed 24-h dietary recall and measurements of body composition and provided a fasting blood sample for measurements of plasma glucose, HbA1c, and serum insulin; homeostasis model assessment of insulin resistance was also derived. RESULTS Energy intake was positively associated with insulin resistance. After the removal of 176 participants with implausible energy intakes (unlikely to be representative of habitual intake), energy intake was more strongly associated with insulin resistance and was also associated with glucose and fat mass index. Energy density was also positively associated with insulin resistance and fat mass index. However, in mutually adjusted analyses, the associations for energy intake remained while those for energy density became nonsignificant. Individual nutrient intakes showed no associations with type 2 diabetes risk markers. CONCLUSIONS Higher total energy intake was strongly associated with high levels of insulin resistance and may help to explain emerging type 2 diabetes risk in childhood. Studies are needed to establish whether reducing energy intake produces sustained favorable changes in insulin resistance and circulating glucose levels.

Dietary intake of young twins: nature or nurture?

BACKGROUND

The early years in life are increasingly recognized as a critical period for the development of diet-related behavioral traits. However, discussions continue on the relative role of genes and the environment in determining dietary intake, particularly in young children for whom detailed dietary information is limited.

OBJECTIVES

This study tested the hypothesis that diet in early childhood is primarily determined by the environment rather than by genes. A secondary aim was to characterize the early childhood diet.

DESIGN

A classic twin design used 3-d dietary data collected at age 21 mo from the Gemini cohort. From the full sample of 2402 families with twins, dietary diaries were available for 1216 twin pairs (384 monozygotic and 832 dizygotic pairs) after exclusions. Intakes of macronutrients, food, and beverages were estimated. Twin analyses quantified the contributions of genetic and environmental factors to population variation in intake.

RESULTS

At age 21 mo, children consumed small portions of a wide range of family foods. The shared environment was the predominant determinant, contributing between 66% (95% CI: 52%, 77%; milk-based desserts) and 97% (95% CI: 95%, 98%; juice) of the variation in intake. Genetic factors were estimated to account for between 4% (95% CI: 0%, 10%; savory snacks) and 18% (95% CI: 14%, 23%; bread) of dietary intake variation.

CONCLUSION

Shared environmental influences are the predominant drivers of dietary intake in very young children, indicating the importance of factors such as the home food environment and parental behaviors.

Plasma retinol and total carotenes and fracture risk after long-term supplementation with high doses of retinol

OBJECTIVE

Observational studies suggest that moderate intakes of retinol and increased circulating retinol levels may increase fracture risk. Easy access to supplements, combined with an aging population, makes this a potentially important association. The aim of this study was to investigate plasma retinol and total carotene concentrations in relation to fracture risk after long-term supplementation with retinol and/or beta-carotene in 998 adults between 1990 and 2007.

METHODS

Participants were 663 men and 335 women in a cancer prevention program who were initially randomized to a retinol (7.5 mg RE/d) or beta-carotene (30 mg/d) supplement between 1990 and 1996. After 1996, all participants received the retinol supplement only. Plasma retinol and total carotene, medication use and various lifestyle factors were measured at annual clinic visits. Fractures were identified by self-report in 2007. The risk for any fracture or osteoporotic fracture was modeled using Cox proportional hazard models.

RESULTS

Over a median follow-up of 7.8 y, 123 participants with plasma samples reported an incident fracture. Although plasma retinol concentrations were markedly higher than those reported in observational studies, no association was observed between plasma retinol and risk for any fracture (hazard ratio [HR], 0.86 μmol/L; 95% confidence interval [CI], 0.65-1.14) or osteoporotic fracture (HR, 0.97 μmol/L; 95% CI, 0.66-1.43). A lower risk for any fracture was suggested with increasing plasma total carotenes (HR, 0.85 μmol/L; 95% CI, 0.71-1.01).

CONCLUSIONS

This study does not support earlier reports of an increased fracture risk associated with increased plasma retinol concentration. The potential for carotenes to prevent fractures deserves further investigation.

The Western dietary pattern is prospectively associated with nonalcoholic fatty liver disease in adolescence

OBJECTIVES

Poor dietary habits have been implicated in the development of nonalcoholic fatty liver disease (NAFLD); however, little is known about the role of specific dietary patterns in the development of NAFLD. We examined prospective associations between dietary patterns and NAFLD in a population-based cohort of adolescents.

METHODS

Participants in the Western Australian Pregnancy Cohort (Raine) Study completed a food frequency questionnaire at 14 years and had liver ultrasound at 17 years (n=995). Healthy and Western dietary patterns were identified using factor analysis and all participants received a z-score for these patterns. Prospective associations between the dietary pattern scores and risk of NAFLD were analyzed using multiple logistic regression.

RESULTS

NAFLD was present in 15.2% of adolescents. A higher Western dietary pattern score at 14 years was associated with a greater risk of NAFLD at 17 years (odds ratio (OR) 1.59; 95% confidence interval (CI) 1.17-2.14; P<0.005), although these associations were no longer significant after adjusting for body mass index at 14 years. However, a healthy dietary pattern at 14 years appeared protective against NAFLD at 17 years in centrally obese adolescents (OR 0.63; 95% CI 0.41-0.96; P=0.033), whereas a Western dietary pattern was associated with an increased risk of NAFLD.

CONCLUSIONS

A Western dietary pattern at 14 years in a general population sample was associated with an increased risk of NAFLD at 17 years, particularly in obese adolescents. In centrally obese adolescents with NAFLD, a healthy dietary pattern may be protective, whereas a Western dietary pattern may increase the risk.

No dose-dependent increase in fracture risk after long-term exposure to high doses of retinol or beta-carotene

Uncertainty remains over whether or not high intakes of retinol or vitamin A consumed through food or supplements may increase fracture risk. This intervention study found no increase in fracture risk among 2,322 adults who took a controlled, high-dose retinol supplement (25,000 IU retinyl palmitate/day) for as long as 16 years. There was some evidence that beta-carotene supplementation decreased fracture risk in men.

INTRODUCTION

There is conflicting epidemiological evidence regarding high intakes of dietary or supplemental retinol and an increased risk for bone fracture. We examined fracture risk in a study administering high doses of retinol and beta-carotene (BC) between 1990 and 2007.

METHODS

The Vitamin A Program was designed to test the efficacy of retinol and BC supplements in preventing malignancies in persons previously exposed to blue asbestos. Participants were initially randomised to 7.5 mg retinol equivalents (RE)/day as retinyl palmitate, 30 mg/day BC or 0.75 mg/day BC from 1990 to 1996; after which, all participants received 7.5 mg RE/day. Fractures were identified by questionnaire and hospital admission data up until 2006. Risk of any fracture or osteoporotic fracture according to cumulative dose of retinol and BC supplementation was examined using conditional logistic regression models adjusting for age, sex, smoking, body mass index, medication use and previous fracture.

RESULTS

Supplementation periods ranged from 1 to 16 years. Of the 2,322 (664 females and 1,658 males) participants, 187 experienced 237 fractures. No associations were observed between cumulative dose of retinol and risk for any fracture (OR per 10 g RE=0.83; 95% CI, 0.63-1.08) or osteoporotic fracture (OR per 10 g RE=0.95; 95% CI 0.64-1.40). Among men, cumulative dose of BC was associated with a slightly reduced risk of any fracture (OR per 10 g=0.89; 95% CI 0.81-0.98) and osteoporotic fracture (OR per 10 g=0.84; 95% CI 0.72-0.97).

CONCLUSIONS

This study observed no increases in fracture risk after long-term supplementation with high doses of retinol and/or beta-carotene.

ADHD is associated with a "Western" dietary pattern in adolescents

OBJECTIVE

To examine the relationship between dietary patterns and ADHD in a population-based cohort of adolescents.

METHOD

The Raine Study is a prospective study following 2,868 live births. At the 14-year follow-up, the authors collected detailed adolescent dietary data, allowing for the determination of major dietary patterns using factor analysis. ADHD diagnoses were recorded according to International Classification of Deiseases, 9th Revision coding conventions. Logistic regression was used to assess the relationship between scores for major dietary pattern and ADHD diagnoses.

RESULTS

Data were available for 1,799 adolescents, and a total of 115 adolescents had an ADHD diagnosis. Two major dietary patterns were identified: "Western" and "Healthy." A higher score for the Western dietary pattern was associated with ADHD diagnosis (odds ratio=2.21, 95% confidence interval=1.18, 4.13) after adjusting for known confounding factors from pregnancy to 14 years. ADHD diagnosis was not associated with the "Healthy" dietary pattern.

CONCLUSION

A Western-style diet may be associated with ADHD.

Polyunsaturated fatty acid intake and blood pressure in adolescents

Evidence that intake of polyunsaturated fatty acids (PUFAs) may modify blood pressure (BP) is generally limited to middle-aged or hypertensive populations. This study examined cross-sectional associations between BP and dietary intake of PUFAs in 814 adolescents aged 13-15 years participating in the Western Australian Pregnancy Cohort (Raine) Study. Fatty acid intakes were assessed using 3-day diet records and resting BP was determined using multiple oscillometric readings. In multivariate regression models, systolic BP was inversely associated with intakes of polyunsaturated (b=-0.436, P<0.01), omega-3 (b=-2.47, P=0.02), omega-6 (b=-0.362, P=0.04) and long chain omega-3 fatty acids (b=-4.37, P=0.04) in boys. Diastolic BP and mean arterial pressure were inversely associated with intakes of long chain omega-3 fatty acids in boys (b=-3.93, P=0.01, b=-4.05, P=0.01, respectively). For specific long-chain omega-3s, significant inverse associations were observed between eicosapentaenoic acid (EPA) and docosahexaenoic acid, such as systolic BP decreasing by 4.7 mm Hg (95% CI -9.3 to -0.1) for a quarter gram increase in EPA, but no significant associations were observed with docosapentaenoic acid. No significant associations were observed in girls, or with the omega-6 to omega-3 ratio. Our results suggest that gender may moderate relationships between fatty acid intake and BP in adolescence.

Relative validity of adolescent dietary patterns: a comparison of a FFQ and 3 d food record

Interest in empirically derived dietary patterns has increased over the past decade. However, relatively few studies have evaluated dietary patterns using different dietary methods, or in young populations. We quantitatively compared dietary patterns from a FFQ with those from a 3 d food record (FR) in a cohort of adolescents. Subjects from the Western Australian Pregnancy Cohort (Raine) Study completed a semi-quantitative FFQ and a 3 d FR at 14 years of age (n 783). Major dietary patterns were identified using exploratory factor analysis on thirty-eight food groups. Dietary pattern z-scores were compared using 95 % limits of agreement (LOA) and Spearman's r. Two major dietary patterns were identified in the FFQ and FR: a 'Healthy' pattern, which was high in fresh fruit, vegetables, whole grains and grilled or canned fish, and a 'Western' pattern, which was high in take-away foods, confectionery, soft drinks, crisps and fried potato. The nutrient profiles of these dietary patterns were similar when estimated by the FFQ and FR. The LOA between dietary pattern scores from the FFQ and FR were - 1·69 to 1·75 ('Healthy') and - 1·89 to 1·82 ('Western'). Minor differences in agreement were observed when boys and girls were analysed separately. Spearman's correlation coefficients between the FFQ and the FR were r 0·45 ('Healthy') and r 0·36 ('Western'). Comparable dietary patterns may be obtained from the FFQ and FR using exploratory factor analysis. This supports the use of major dietary patterns identified using the FFQ in this adolescent cohort.

Serum levels of folate, lycopene, β-carotene, retinol and vitamin E and prostate cancer risk

Previous studies relating increased serum levels of folate and fat-soluble vitamins to prostate cancer risk have variously shown null associations or to either decrease or increase the risk of developing prostate cancer. Prospective studies of serum folate levels have been reported to show a null association and increased serum levels to either decrease or increase the risk of subsequently developing prostate cancer. Similarly, serum β-carotene and lycopene levels have either been reported to be inversely correlated or not associated with prostate cancer risk. Using a prospective nested case-control study design, which minimized the possibility of disease effects on serum-vitamin concentrations, we report null associations for serum concentrations of folate, lycopene, β-carotene, vitamin A and vitamin E, and subsequent development of prostate cancer.

Dietary glycaemic carbohydrate in relation to the metabolic syndrome in adolescents: comparison of different metabolic syndrome definitions

AIMS

High dietary glycaemic carbohydrate, as measured by the dietary glycaemic index and glycaemic load has been associated with increased risk of the metabolic syndrome in adults, but limited research exists for younger populations. We aimed to evaluate associations between dietary glycaemic carbohydrate and insulin resistance or the prevalence of the metabolic syndrome defined by three different criteria in a population-based adolescent cohort.

METHODS

Diet was assessed using 3 day food records in 769 adolescents aged 13-15 years participating in the Western Australian Pregnancy Cohort (Raine) Study. The metabolic syndrome was identified using age-specific adolescent definitions from the International Diabetes Federation, the National Cholesterol Education Program Adult Treatment Panel III and a population-derived 'high-risk' metabolic cluster algorithm. Presence of a high waist circumference was mandatory only in the International Diabetes Federation definition. Insulin resistance was measured using homeostasis model assessment (HOMA-IR).

RESULTS

The prevalence of the metabolic syndrome as defined by the International Diabetes Federation and the Adult Treatment Panel III was 3.6 and 4.0%, respectively; 25.9% of subjects were classified into the high-risk cluster. Significantly increased odds of International Diabetes Federation-defined metabolic syndrome were independently associated with a 20 unit glycaemic load increase (odds ratio 2.18; 95% confidence interval 1.26-3.78) and a 30 g carbohydrate increase (odds ratio 3.86; 95% confidence interval 1.80-8.28). No significant associations were observed when using the Adult Treatment Panel III, or the cluster-defined metabolic syndrome, or with HOMA-IR.

CONCLUSIONS

This study supports the concept that high dietary glycaemic carbohydrate is associated with a higher prevalence of the metabolic syndrome in adolescents. However, relationships vary according to the definition of the metabolic syndrome used, with waist circumference a potentially relevant factor.

Dietary patterns and markers for the metabolic syndrome in Australian adolescents

BACKGROUND AND AIMS

Overweight and other risk factors for cardiovascular disease (CVD) as well as their clustering, are increasingly prevalent among adolescents. We examined dietary patterns, CVD risk factors, and the clustering of these risk factors in 1139 14-year-olds living in Western Australia.

METHODS AND RESULTS

Usual dietary intake was assessed using a food frequency questionnaire. Two dietary patterns, 'Western' and 'Healthy', were identified using factor analysis. Associations between these dietary patterns and BMI, waist circumference, systolic blood pressure, fasting levels of serum glucose, insulin, total cholesterol, HDL-C, LDL-C, triglycerides and insulin resistance were assessed using ANOVA. Cluster analysis identified a high risk group (the 'high risk metabolic cluster') with features akin to adult metabolic syndrome. Belonging to the 'high risk metabolic cluster' was examined in relation to dietary patterns using logistic regression, adjusting for aerobic fitness and socio-demographic factors. Higher 'Western' dietary pattern scores were associated with greater odds for the 'high risk metabolic cluster' (p for trend=0.02) and greater mean values for total cholesterol (p for trend=0.03), waist circumference (p for trend=0.03) and BMI (p for trend=0.02) in girls, but not boys. Scores for the 'Healthy' dietary pattern were not related to the 'high risk metabolic cluster' but were inversely associated with serum glucose in boys and girls (p for trend=0.01 and 0.04, respectively) and were positively associated with HDL-C in boys (p for trend=0.02).

CONCLUSIONS

Dietary patterns are associated with CVD risk factors and the clustering of these risk factors in adolescence.

The association between dietary patterns and mental health in early adolescence

OBJECTIVE

To investigate the associations between dietary patterns and mental health in early adolescence.

METHOD

The Western Australian Pregnancy Cohort (Raine) Study is a prospective study of 2900 pregnancies recruited from 1989-1992. At 14 years of age (2003-2006; n=1324), the Child Behaviour Checklist (CBCL) was used to assess behaviour (characterising mental health status), with higher scores representing poorer behaviour. Two dietary patterns (Western and Healthy) were identified using factor analysis and food group intakes estimated by a 212-item food frequency questionnaire. Relationships between dietary patterns, food group intakes and behaviour were examined using general linear modelling following adjustment for potential confounding factors at age 14: total energy intake, body mass index, physical activity, screen use, family structure, income and functioning, gender and maternal education at pregnancy.

RESULTS

Higher total (b=2.20, 95% CI=1.06, 3.35), internalizing (withdrawn/depressed) (b=1.25, 95% CI=0.15, 2.35) and externalizing (delinquent/aggressive) (b=2.60, 95% CI=1.51, 3.68) CBCL scores were significantly associated with the Western dietary pattern, with increased intakes of takeaway foods, confectionary and red meat. Improved behavioural scores were significantly associated with higher intakes of leafy green vegetables and fresh fruit (components of the Healthy pattern).

CONCLUSION

These findings implicate a Western dietary pattern in poorer behavioural outcomes for adolescents. Better behavioural outcomes were associated with a higher intake of fresh fruit and leafy green vegetables.

Dietary patterns and surgically treated benign prostatic hyperplasia: a case control study in Western Australia

OBJECTIVES

To investigate dietary patterns and food intake as risk factors for surgically treated benign prostatic hyperplasia (BPH), as few risk factors have been established for BPH and recently there has been some interest in a role for diet in the development of BPH.

PATIENTS, SUBJECTS AND METHODS

A case-control study was conducted in Western Australia (WA) during 2001 and 2002. BPH cases were men with a diagnosis of BPH hospitalized for their first prostatectomy. Controls were frequency matched for age and sex from the WA electoral roll. A previously evaluated food-frequency questionnaire (FFQ) collected information on usual dietary intake 10 years earlier. Factor analysis identified dietary patterns in the FFQ data. Effects of dietary patterns and food intakes on the risk of BPH were examined using unconditional logistic regression, adjusting for various confounders.

RESULTS

In all, 406 cases and 462 controls (aged 40-75 years) provided data. Three dietary patterns were identified, i.e. 'Vegetable', 'Western' and 'Health Conscious'. BPH risk was not associated with the 'Health Conscious' or 'Western' patterns, but there was a lower risk with an increasing score for the 'Vegetable' pattern (odds ratio 0.78, 95% confidence interval 0.63-0.98). BPH risk was significantly and inversely related to the intake of total vegetables, dark yellow vegetables, other vegetables, tofu and red meat. There was a higher risk of BPH with increasing intake of high-fat dairy products.

CONCLUSIONS

These results indicate that vegetables, soy products, red meat and high-fat dairy foods might be important in the development of BPH.

Mortality of former crocidolite (blue asbestos) miners and millers at Wittenoom

BACKGROUND

Blue asbestos was mined and milled at Wittenoom in Western Australia between 1943 and 1966.

METHODS

Nearly 7000 male workers who worked at the Wittenoom mine and mill have been followed up using death and cancer registries throughout Australia and Italy to the end of 2000. Person-years at risk were derived using two censoring dates in order to produce minimum and maximum estimates of asbestos effect. Standardised mortality ratios (SMRs) compare the mortality of the former Wittenoom workers with the Western Australian male population.

RESULTS

There have been 190 cases of pleural and 32 cases of peritoneal mesothelioma in this cohort of former workers at Wittenoom. Mortality from lung cancer (SMR = 1.52), pneumoconiosis (SMR = 15.5), respiratory diseases (SMR = 1.58), tuberculosis (SMR = 3.06), digestive diseases (SMR = 1.47), alcoholism (SMR = 2.24) and symptoms, signs and ill defined conditions (SMR = 2.00) were greater in this cohort compared to the Western Australian male population.

CONCLUSION

Asbestos related diseases, particularly malignant mesothelioma, lung cancer and pneumoconiosis, continue to be the main causes of excess mortality in the former blue asbestos miners and millers of Wittenoom.

Fruit, vegetable, vitamin A intakes, and prostate cancer risk

Prostate cancer risk was examined in relation to intakes of fruit, vegetables, beta-carotene and retinol. Subjects were a cohort of 1985 men previously to asbestos who participated in a cancer prevention programme of beta-carotene and retinol supplements that commenced in July 1990. Diet was assessed at entry to the programme. Ninety-seven cases of prostate cancer were identified during follow-up until the end of 2004. A decreased prostate cancer risk was observed with increasing intakes of vitamin C-rich vegetables, including bell peppers and broccoli. Fruit, other vegetables and vitamin A intakes did not appear to be strong factors in the development of prostate cancer in this study.

Occupational risk factors for prostate cancer and benign prostatic hyperplasia: a case-control study in Western Australia

OBJECTIVE

To assess the association of selected occupational exposures with risk of prostate cancer and with risk of benign prostatic hyperplasia (BPH).

METHODS

This population-based case-control study recruited 606 men with a diagnosis of confirmed prostate cancer, 400 men who had undergone their first prostatectomy for BPH and 471 male controls randomly selected from the electoral roll between 1 August 2001 and 1 October 2002 in Western Australia. chi(2) tests and logistic regressions were used for univariate and multivariate analyses to investigate the association of the two outcomes with occupational exposure to pesticides, fertilisers, metals, wood dust, oils, diesel exhaust and polyaromatic hydrocarbons (PAHs).

RESULTS

Exposure to toxic metals at a non-substantial level increased the risk of BPH (odds ratio (OR) 1.39, 95% confidence interval (CI) 1.1 to 1.84) and led to a non-significant excess risk of prostate cancer (OR 1.25, 95% CI 0.96 to 1.61). Non-significant excess risks were observed for prostate cancer after exposure to oils other than mineral oil (OR 1.54, 95% CI 0.95 to 2.51) and for BPH after exposure to PAHs (OR 1.20, 95% CI 0.91 to 1.58). A non-statistically significant protective effect for prostate cancer was seen after exposure to organophosphate pesticides (OR 0. 69, 95% CI 0.43 to 1.12). No other associations were found for either prostate cancer or BPH and no dose-response relationships were seen for the exposures investigated.

CONCLUSIONS

These results do not provide evidence that any of the occupational factors examined are risk factors for either prostate cancer or BPH.

The risk of lung cancer with increasing time since ceasing exposure to asbestos and quitting smoking

OBJECTIVES

To examine if the risk of lung cancer declines with increasing time since ceasing exposure to asbestos and quitting smoking, and to determine the relative asbestos effect between non-smokers and current smokers.

METHODS

A cohort study of 2935 former workers of the crocidolite mine and mill at Wittenoom, who responded to a questionnaire on smoking first issued in 1979 and on whom quantitative estimates of asbestos exposure are known. Conditional logistic regression was used to relate asbestos exposure, smoking category, and risk of lung cancer.

RESULTS

Eighteen per cent of the cohort reported never smoking; 66% of cases and 50% of non-cases were current smokers. Past smokers who ceased smoking within six years of the survey (OR = 22.1, 95% CI 5.6 to 87.0), those who ceased smoking 20 or more years before the survey (OR = 1.9, 95% CI 0.50 to 7.2), and current smokers (<20 cigarettes per day (OR = 6.8, 95% CI 2.0 to 22.7) or >20 cigarettes per day (OR = 13.2, 95% CI 4.1 to 42.5)) had higher risks of lung cancer compared to never smokers after adjusting for asbestos exposure and age. The asbestos effect between non-smokers and current smokers was 1.23 (95% CI 0.35 to 4.32).

CONCLUSION

Persons exposed to asbestos and tobacco but who subsequently quit, remain at an increased risk for lung cancer up to 20 years after smoking cessation, compared to never smokers. Although the relative risk of lung cancer appears higher in never and ex-smokers than in current smokers, those who both smoke and have been exposed to asbestos have the highest risk; this study emphasises the importance of smoking prevention and smoking cessation programmes within this high risk cohort.

Plasma vitamin concentrations and incidence of mesothelioma and lung cancer in individuals exposed to crocidolite at Wittenoom, Western Australia

Increased rates of death from asbestos-related diseases have been reported in former workers and residents exposed to crocidolite (blue asbestos) at Wittenoom (Western Australia). The relationships between plasma concentrations of retinol, carotene and vitamin E and incidence of mesothelioma and lung cancer in a cohort of people from this town were examined. The relationships were evaluated by survival analyses using data obtained at the first visit, at each visit and with the rate of change of each vitamin during the period of follow-up. Of 1953 study participants, 65 developed mesothelioma during the follow-up, and 47 developed lung cancer. A lower incidence of mesothelioma was related to plasma concentrations of retinol at the first visit [hazard ratio (HR)=0.63, 95% confidence interval=0.41-0.99], and to measurements at each visit (HR=0.71, 95% confidence interval=0.50-1.00). Plasma carotene concentrations at the first measurement, but not during the follow-up period, were associated with lower incidence of lung cancer in men and in workers. No significant associations were found between carotene concentrations and incidence of mesothelioma. Vitamin E concentrations were not significantly associated with mesothelioma or lung cancer incidence. These findings suggest that people with chronically low plasma levels of retinol have increased risk of developing mesothelioma and lung cancer.