Can social cognitive theory constructs explain socio-economic variations in adolescent eating behaviours? A mediation analysis

Adolescents of low socio-economic position (SEP) are less likely than those of higher SEP to consume diets in line with current dietary recommendations. The reasons for these SEP variations remain poorly understood. We investigated the mechanisms underlying socio-economic variations in adolescents’ eating behaviours using a theoretically derived explanatory model. Data were obtained from a community-based sample of 2529 adolescents aged 12–15 years, from 37 secondary schools in Victoria, Australia. Adolescents completed a web-based survey assessing their eating behaviours, self-efficacy for healthy eating, perceived importance of nutrition and health, social modelling and support and the availability of foods in the home. Parents provided details of maternal education level, which was used as an indicator of SEP. All social cognitive constructs assessed mediated socio-economic variations in at least one indicator of adolescents’ diet. Cognitive factors were the strongest mediator of socio-economic variations in fruit intakes, while for energy-dense snack foods and fast foods, availability of energy-dense snacks at home tended to be strong mediators. Social cognitive theory provides a useful framework for understanding socio-economic variations in adolescent's diet and might guide public health programmes and policies focusing on improving adolescent nutrition among those experiencing socio-economic disadvantage.

Children's liking and wanting of snack products : influence of shape and flavour

Background : Children's food choices are guided by their preferences. However, these preferences may change due to repeated exposure.

Methods : This study investigated children's (n = 242, 7–12 yrs-old) liking and wanting for snacks over 3 weeks of daily consumption. The snacks differed in size (small vs large) or flavour (sweet vs sweet-sour). Two conditions were designed: 1) a monotonous group in which children continuously consumed the same snack across the 3 weeks, and 2) a free choice group in which children were allowed to freely choose amongst 3 different flavours of the snack each day during 3 weeks.

Results : Shape influenced long-term liking, i.e. small shaped snacks remained stable in liking over repeated consumption, whereas large shaped snacks with the same flavour decreased in liking. Mean wanting ratings for all snack products decreased over 3 weeks daily consumption. Flavour did not significantly influence liking and wanting over time. The ability to freely choose amongst different flavours tended to decrease children's liking (p < 0.1) and wanting (p < 0.001) for these products. Changes in liking rather than initial liking was the best predictor of snack choice during the intervention.

Conclusion : Wanting rather than liking was most affected by repeated daily consumption of snack foods over three weeks. In order to increase the likelihood that children will repeatedly eat a food product, smaller sized healthy snacks are preferred to larger sized snacks. Future research should focus on stabilizing wanting over repeated consumption.

Healthy minds for country youth : help-seeking for depression among rural adolescents

Objective: To assess depression recognition, barriers to accessing help from health professionals and potential sources of help for depression among rural adolescents.

Design: Cross-sectional survey.

Setting: Two rural secondary schools in south-east South Australia.

Participants: Seventy-four secondary school students aged 14 to 16 years.

Main outcome measure(s): Depression recognition was measured using a depression vignette. Helpfulness of professionals, barriers to seeking help and help-seeking behaviours for depression were assessed by self-report questionnaire.

Results: Depression was identified in the vignette by 73% (n = 54) of participants. Participants indicated that it would be more helpful for the vignette character to see other health professionals (98.6%, 95% CI, 92.0–100.0%) than a doctor (82.4%, 72.1–89.6%). Barriers to seeking help from doctors and other health professionals were categorised into logistical and personal barriers. Participants agreed more strongly to personal (mean = 2.86) than logistical barriers (mean = 2.67, P < 0.05) for seeing a doctor. Boys and girls responded differently overall, and to personal barriers to seeing an other health professional. Sources of help were divided into three categories: formal, informal and external. Informal sources of help (mean = 4.02) were identified as more helpful than both formal (mean = 3.66) and external sources (mean = 3.72, P < 0.001). Gender differences were observed within and between the three sources of help categories.

Conclusions: Recognising symptoms of depression was demonstrated in this study. Helpfulness of professionals, barriers to seeking help and potential sources of help for depression were identified. More work is required for improving depression literacy and providing effective interventions specifically for rural adolescents.

The effect of fiscal policy on diet, obesity and chronic disease : a systematic review

Objective To assess the effect of food taxes and subsidies on diet, body weight and health through a systematic review of the literature.

Methods We searched the English-language published and grey literature for empirical and modelling studies on the effects of monetary subsidies or taxes levied on specific food products on consumption habits, body weight and chronic conditions. Empirical studies were dealing with an actual tax, while modelling studies predicted outcomes based on a hypothetical tax or subsidy.

Findings Twenty-four studies met the inclusion criteria: 13 were from the peer-reviewed literature and 11 were published on line. There were 8 empirical and 16 modelling studies. Nine studies assessed the impact of taxes on food consumption only, 5 on consumption and body weight, 4 on consumption and disease and 6 on body weight only. In general, taxes and subsidies influenced consumption in the desired direction, with larger taxes being associated with more significant changes in consumption, body weight and disease incidence. However, studies that focused on a single target food or nutrient may have overestimated the impact of taxes by failing to take into account shifts in consumption to other foods. The quality of the evidence was generally low. Almost all studies were conducted in high-income countries.

Conclusion Food taxes and subsidies have the potential to contribute to healthy consumption patterns at the population level. However, current evidence is generally of low quality and the empirical evaluation of existing taxes is a research priority, along with research into the effectiveness and differential impact of food taxes in developing countries.

Cholesterol-lowering effects of plant sterol esters and non-esterified stanols in margarine, butter and low-fat foods

Objectives: To determine the efficacy on plasma cholesterol-lowering of plant sterol esters or non-esterified stanols eaten within low-fat foods as well as margarine.
Design: Randomised, controlled, single-blind study with sterol esters and non-esterified plant stanols provided in breakfast cereal, bread and spreads. Study 1 comprised 12 weeks during which sterol esters (2.4 g) and stanol (2.4 g) -containing foods were eaten during 4 week test periods of cross-over design following a 4 week control food period. In Study 2, in a random order cross-over design, a 50% dairy fat spread with or without 2.4 g sterol esters daily was tested.
Subjects: Hypercholesterolaemic subjects; 22 in study 1 and 15 in study 2.
Main outcome measures: Plasma lipids, plasma sterols, plasma carotenoids and tocopherols.
Results: Study 1¾median LDL cholesterol was reduced by the sterol esters (-13.6%; P<0.001 by ANOVA on ranks; P<0.05 by pairwise comparison) and by stanols (-8.3%; P=0.003, ANOVA and <0.05 pairwise comparison). With sterol esters plasma plant sterol levels rose (35% for sitosterol, 51% for campesterol; P<0.001); plasma lathosterol rose 20% (P=0.03), indicating compensatory increased cholesterol synthesis. With stanols, plasma sitosterol fell 22% (P=0.004), indicating less cholesterol absorption. None of the four carotenoids measured in plasma changed significantly. In study 2, median LDL cholesterol rose 6.5% with dairy spread and fell 12.2% with the sitosterol ester fortified spread (P=0.03 ANOVA and <5% pairwise comparison).
Conclusion: 1. Plant sterol esters and non-esterified stanols, two-thirds of which were incorporated into low-fat foods, contributed effectively to LDL cholesterol lowering, extending the range of potential foods. 2. The LDL cholesterol-raising effect of butter fat could be countered by including sterol esters. 3. Plasma carotenoids and tocopherols were not reduced in this study.

The assessment of тт-тт selective stationary phases for two-dimensional HPLC analysis of foods : application to the analysis of coffee

Differences between alkyl, dipole–dipole, hydrogen bonding, and π-π selective surfaces represented by non-resonance and resonance π-stationary phases have been assessed for the separation of ‘Ristretto’ café espresso by employing 2DHPLC techniques with C18 phase selectivity detection. Geometric approach to factor analysis (GAFA) was used to measure the detected peaks (N), spreading angle (β), correlation, practical peak capacity (n_p) and percentage usage of the separations space, as an assessment of selectivity differences between regional quadrants of the two-dimensional separation plane. Although all tested systems were correlated to some degree to the C18 dimension, regional measurement of separation divergence revealed that performance of specific systems was better for certain sample components. The results illustrate that because of the complexity of the ‘real’ sample obtaining a truly orthogonal two-dimensional system for complex samples of natural origin may be practically impossible.

Healthy eating and obesity prevention for preschoolers : a randomised controlled trial

Background
Developing effective prevention and intervention programs for the formative preschool years is seen as an essential step in combating the obesity epidemic across the lifespan. The overall goal of the current project is to measure the effectiveness of a healthy eating and childhood obesity prevention intervention, the MEND (Mind Exercise Nutrition Do It!) program that is delivered to parents of children aged 2-4 years.

Methods/Design
This randomised controlled trial will be conducted with 200 parents and their 2-4 year old children who attend the MEND 2-4 program in metropolitan and regional Victoria. Parent-child dyads will attend ten 90-minute group workshops. These workshops focus on general nutrition, as well as physical activity and behaviours. They are typically held at community or maternal and child health centres and run by a MEND 2-4 trained program leader. Child eating habits, physical activity levels and parental behaviours and cognitions pertaining to nutrition and physical activity will be assessed at baseline, the end of the intervention, and at 6 and 12 months post the intervention. Informed consent will be obtained from all parents, who will then be randomly allocated to the intervention or wait-list control group.

Discussion
Our study is the first RCT of a healthy eating and childhood obesity prevention intervention targeted specifically to Australian parents and their preschool children aged 2-4 years. It responds to the call by experts in the area of childhood obesity and child health that prevention of overweight in the formative preschool years should focus on parents, given that parental beliefs, attitudes, perceptions and behaviours appear to impact significantly on the development of early overweight. This is 'solution-oriented' rather than 'problem-oriented' research, with its focus being on prevention rather than intervention. If this is a positive trial, the MEND2-4 program can be implemented as a national program.

Trial Registration
Australian New Zealand Clinical Trials Registry ACTRN12610000200088

Who is eating where? Findings from the SESAW study

Objective: Foods prepared outside of the home have been linked to less-than-ideal nutrient profiles for health. We examine whether the locations where meals are prepared and consumed are associated with socio-economic predictors among women.
Design: A cross-sectional study using self-reported data. We examined multiple locations where meals are prepared and consumed: (i) at home; (ii) fast food eaten at home; (iii) fast food eaten at the restaurant; (iv) total fast food; (v) non-fast-food restaurant meals eaten at home; (vi) non-fast-food restaurant meals eaten at the restaurant; and (vii) all non-fast-food restaurant meals. Multilevel logistic regression was used to determine whether frequent consumption of meals from these sources varied by level of education, occupation, household income and area-level disadvantage.
Setting: Metropolitan Melbourne, Australia.
Subjects: A total of 1328 women from forty-five neighbourhoods randomly sampled for the SocioEconomic Status and Activity in Women study.
Results: Those with higher educational qualifications or who were not in the workforce (compared with those in professional employment) were more likely to report frequent consumption of meals prepared and consumed at home. High individual and area-level socio-economic characteristics were associated with a lower likelihood of frequent consumption of fast food and a higher likelihood of frequent consumption of meals from non-fast-food sources. The strength and significance of relationships varied by place of consumption.
Conclusions: The source of meal preparation and consumption varied by socioeconomic predictors. This has implications for policy makers who need to continue to campaign to make healthy alternatives available in out-of-home food sources.