Therese A. O'Sullivan

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.

A good-quality breakfast is associated with better mental health in adolescence

OBJECTIVE Breakfast consumption has been associated with better mental health in adulthood, but the relationship between breakfast and mental health in adolescence is less well known. The aims of the present study were to evaluate breakfast quality in a cohort of adolescents and to investigate associations with mental health. DESIGN Cross-sectional population-based study. Breakfast quality was assessed by intake of core food groups at breakfast, as determined from 3 d food diaries. Mental health was assessed using the Child Behaviour Checklist (CBCL), with higher scores representing poorer behaviour. SETTING The Western Australian Pregnancy Cohort (Raine) Study, Perth, Western Australia. SUBJECTS Eight hundred and thirty-six males and females aged between 13 and 15 years. RESULTS Mean mental health score as assessed by the CBCL was 45.24 (sd 11.29). A high-quality breakfast consisting of at least three food groups was consumed by 11 % of adolescents, while 7 % of adolescents did not consume any items from core food groups on average over the 3 d period. The two most common core food groups consumed at breakfast in this population were dairy products followed by breads and cereals. For every additional food group eaten at breakfast, the associated total mental health score decreased by 1.66 (95 % CI -2.74, -0.59) after adjustment for potential confounding factors, representing an improvement in mental health score. CONCLUSION These findings support the concept that breakfast quality is an important component in the complex interaction between lifestyle factors and mental health in early adolescence.

Energy drink consumption among young Australian adults: Associations with alcohol and illicit drug use

BACKGROUND Energy drinks are becoming increasingly popular among young people. The purpose of this study was to determine the prevalence of energy drink consumption and its associations with socio-demographic characteristics, alcohol, cigarette and illicit drug use in a population-based sample of young adults participating in the Western Australian Pregnancy Cohort (Raine) Study. METHODS We used self-administered questionnaires to assess energy drink consumption patterns, alcohol intake, cigarette and illicit drug use at the 20-year cohort follow-up. Data was also collected on socio-demographics, physical activity, body mass index (BMI) and dietary intake. Our sample included 1234 participants (47% male, mean age 20 ± 0.5 years). We considered energy-drink consumption as a categorical (users versus non-users) variable. RESULTS Overall, 48% of participants consumed energy drinks at least once per month, with an average intake of 1.31 ± 0.75 cans per day amongst energy drink users. The most significant correlates of energy drink use were being in part-time or full-time employment, being male, being a cigarette smoker, having heavier alcoholic spirit consumption patterns and being an ecstasy user (all p<0.05). No significant associations were observed with BMI or dietary intake. CONCLUSIONS Australian energy drink users tend to have heavier alcohol consumption patterns be a cigarette smoker and use illicit drugs relative to non-users. More research is needed regarding the health risks associated with energy drink use in young adults, including their possible role in the development of substance abuse problems.

Tackling overweight and obesity: does the public health message match the science?

BackgroundDespite the increasing understanding of the mechanisms relating to weight loss and maintenance, there are currently no validated public health interventions that are able to achieve sustained long-term weight loss or to stem the increasing prevalence of obesity in the population. We aimed to examine the models of energy balance underpinning current research about weight-loss intervention from the field of public health, and to determine whether they are consistent with the model provided by basic science. EMBASE was searched for papers published in 2011 on weight-loss interventions. We extracted details of the population, nature of the intervention, and key findings for 27 articles.DiscussionMost public health interventions identified were based on a simple model of energy balance, and thus attempted to reduce caloric consumption and/or increase physical activity in order to create a negative energy balance. There appeared to be little consideration of homeostatic feedback mechanisms and their effect on weight-loss success. It seems that there has been a lack of translation between recent advances in understanding of the basic science behind weight loss, and the concepts underpinning the increasingly urgent efforts to reduce excess weight in the population.SummaryPublic health weight-loss interventions seem to be based on an outdated understanding of the science. Their continued failure to achieve any meaningful, long-term results reflects the need to develop intervention science that is integrated with knowledge from basic science. Instead of asking why people persist in eating too much and exercising too little, the key questions of obesity research should address those factors (environmental, behavioral or otherwise) that lead to dysregulation of the homeostatic mechanism of energy regulation. There is a need for a multidisciplinary approach in the design of future weight-loss interventions in order to improve long-term weight-loss success.

Changes in Dairy Food and Nutrient Intakes in Australian Adolescents

Dairy nutrients, such as calcium, are particularly important in adolescence, a critical time for growth and development. There are limited Australian data following individuals through adolescence, evaluating changes in dairy nutrient and dairy product consumption. We used a validated food frequency questionnaire to investigate consumption in adolescents participating in both the 14 and 17 year follow-ups of the Western Australian Pregnancy Cohort (Raine) Study. Most adolescents did not reach age and gender specific recommended daily intakes for calcium or magnesium at 14 years, and this decreased as they aged to 17 years (from 33.0% to 29.2% meeting for calcium, P < 0.05, and from 33.6% to 20.5% meeting for magnesium, P < 0.01). Mean intakes of calcium, potassium, riboflavin and vitamin A also decreased with age (P < 0.01). Mean dairy intake decreased from 536 ± 343 g/day to 464 ± 339 g/day (P < 0.01), due mostly to a decrease in regular milk, although flavoured milk consumption increased in boys. Cheese and butter were the only products to show a significantly increased consumption over the period. Girls decreased from 2.2 to 1.9 serves/day of dairy, while boys remained relatively steady at 2.9 to 2.8 serves/day. Our findings suggest that dairy product consumption decreases over adolescence. This may have implications for bone mass, development and later health.

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

Diabet. Med. 27, 770–778 (2010)

Lower Fructose Intake May Help Protect Against Development of Nonalcoholic Fatty Liver in Adolescents With Obesity

Objectives: Although obesity is a major risk factor for nonalcoholic fatty liver (NAFL), not all individuals with obesity develop the condition, suggesting that other factors such as diet may also contribute to NAFL development. We evaluated associations between fructose and total sugar intake and subsequent diagnosis of NAFL in adolescents with obesity and without obesity in a population-based cohort. Methods: Adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study completed 3-day food records and body mass index measurement at age 14 years. At age 17 years, participants underwent abdominal ultrasound to determine NAFL status. Multivariable logistic regression models were used to analyse associations between energy-adjusted fructose and total sugar intake and NAFL status. Food diaries and liver assessments were completed for 592 adolescents. Results: The prevalence of NAFL at age 17 was 12.8% for the total group and 50% for adolescents with obesity. Fructose intake did not significantly differ between adolescents with or without NAFL in our cohort as a whole. Among adolescents with obesity, those without NAFL had significantly lower energy-adjusted fructose intake at age 14 years compared with those with NAFL (mean ± standard deviation [SD] 38.8 ± 19.8 g/day, vs 55.7 ± 14.4 g/day, P = 0.02). Energy-adjusted fructose intake was independently associated with NAFL in adolescents with obesity (OR [odds ratio] 1.09, 95% CI 1.01–1.19, P = 0.03) after the adjustment for confounding factors. Energy-adjusted total sugar intake showed less significance (OR 1.03, 95% CI 0.999–1.07, P = 0.06). No significant associations were observed in other body mass index categories. Conclusions: Lower fructose consumption in adolescents with obesity at 14 years is associated with a decreased risk of NAFL at 17 years. Fructose rather than overall sugar intake may be more physiologically relevant in this association.

Low intake of B-vitamins is associated with poor adolescent mental health and behaviour

OBJECTIVE The current prevalence of mental health problems in Western populations is approximately 20% and half of all adult mental health disorders are estimated to originate in adolescence. Diet plays an important role in modulating psychological wellbeing and B-vitamins are vital for the synthesis of neurotransmitters such as serotonin. We aimed to examine the relationship between B-group vitamins and adolescent mental health and behaviour. METHODS This is a cross-sectional analysis of the West Australian Pregnancy Cohort (Raine) Study. The 17-year follow-up included collection of a food frequency questionnaire allowing B-vitamin intake calculation. Mental health was assessed using the Youth Self Report (YSR) which measures total, internalising (withdrawn/depressed) and externalising (aggressive/delinquent) behaviour scores. Multiple linear regression was used to analyse associations between B-vitamins and mental health with adjustment for relevant confounders (n=709). RESULTS Lower intake of vitamins B1, B2, B3, B5, B6, and folate was associated with higher externalising behaviour scores (p ≤ 0.05). Reduced intake of vitamin B6 and folate was associated with higher internalising behaviour scores (p ≤ 0.05). CONCLUSIONS Poor nutrition may contribute to the pathogenesis of mental health problems in adolescence. The role of B-vitamins requires further investigation in randomised controlled trials.

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.

Dietary fructose in relation to blood pressure and serum uric acid in adolescent boys and girls

Evidence that fructose intake may modify blood pressure is generally limited to adult populations. This study examined cross-sectional associations between dietary intake of fructose, serum uric acid and blood pressure in 814 adolescents aged 13–15 years participating in the Western Australian Pregnancy Cohort (Raine) Study. Energy-adjusted fructose intake was derived from 3-day food records, serum uric acid concentration was assessed using fasting blood and resting blood pressure was determined using repeated oscillometric readings. In multivariate linear regression models, we did not see a significant association between fructose and blood pressure in boys or girls. In boys, fructose intake was independently associated with serum uric acid (P<0.01), and serum uric acid was independently associated with systolic blood pressure (P<0.01) and mean arterial pressure (P<0.001). Although there are independent associations, there is no direct relationship between fructose intake and blood pressure. Our data suggest that gender may influence these relationships in adolescence, with significant associations observed more frequently in boys than girls.