Tania Prvan

Evaluation of general nutrition knowledge in elite Australian athletes

The aim of the present study was to investigate and benchmark the level of general nutrition knowledge in elite Australian athletes (EA) against a similar aged community (CM) and criterion sample with dietetic training (DT). EA (n 175), CM (n 116) and DT (n 53) completed the General Nutrition Knowledge Questionnaire (GNKQ), which assesses four domains (sections A-D) of general nutrition knowledge (section A: dietary guidelines; section B: sources of nutrients; section C: choosing everyday foods; section D: diet-disease relationships). Age, sex and education level were collected in all groups, and athletic calibre and sport type (team or individual) in EA. Dietitians and nutrition scientists (n 53) re-examined the GNKQ for content validity, resulting in instrument revision (R-GNKQ; ninety-six items). Psychometric assessment (internal consistency: Cronbach-α; test-retest: Spearman rank correlation) was performed in a sub-sample (n 28). Independent t tests, ANOVA and ANCOVA (χ² for categorical variables) were used to assess between-group differences. DT scored higher than EA and CM in all sub-sections and overall (P < 0·005). EA scored lower than CM in GNKQ for section B (P < 0·005) and overall (P < 0·005), and in R-GNKQ for section B (P < 0·005), section C (P < 0·005), section D (P = 0·006) and overall (P < 0·005). Overall score was influenced by age (P = 0·036 for GNKQ: P = 0·053 for R-GNKQ), sex (P = 0·016 for GNKQ: P = 0·003 for R-GNKQ) and athletic calibre (P = 0·029 for R-GNKQ only), but not level of education, living situation or ethnicity. EA and CM performed best on section A and worst on D. EA had lower overall general knowledge scores than CM. This was significantly influenced by age and sex.

An annotated bibliography of application papers using certain classes of fractional factorial and related designs

In this paper we provide an annotated bibliography of about 140 papers which have appeared in journals in a variety of areas in the last 5 years and in which a fractional factorial design has been used. For each reference, we have indicated the design or designs used and whether or not the responses are given in the paper. The level of detail given in these papers makes them suitable sources for examples in a course on the design and analysis of experiments.

Statistical Laboratories Using Minitab, SPSS and Excel: A Practical Comparison

Summary This article discusses three statistical laboratories – on descriptive statistics, statistical inference and regression – for introductory statistics courses. They are presented in Minitab, SPSS (Statistical Package for the Social Sciences) and Excel, three packages widely used in statistics education, and are available from the Web.

Relationship Between General Nutrition Knowledge and Dietary Quality in Elite Athletes.

UNLABELLED This study investigated the association between general nutrition knowledge and dietary quality in a convenience sample of athletes (≥ state level) recruited from four Australian State Sport Institutes. General nutrition knowledge was measured by the validated General Nutrition Knowledge Questionnaire and diet quality by an adapted version of the Australian Recommended Food Score (A-ARFS) calculated from food frequency questionnaire data. Analysis of variance and linear modeling were used to assess relationships between variables. DATA mean (Standard Deviation). A total of 101 athletes (Males: 37; Females: 64), 18.6 (4.6) years were recruited mainly from team sports (72.0%). Females scored higher than males for both nutrition knowledge (Females: 59.9%; Males: 55.6%; p = .017) and total A-ARFS (Females: 54.2% Males: 49.4%; p = .016). There was no significant influence of age, level of education, athletic caliber or team/individual sport participation on nutrition knowledge or total A-ARFS. However, athletes engaged in previous dietetic consultation had significantly higher nutrition knowledge (61.6% vs. 56.6%; p = .034) but not total A-ARFS (53.6% vs. 52.0%; p = .466). Nutrition knowledge was weakly but positively associated with total A-ARFS (r = .261, p= .008) and A-ARFS vegetable subgroup (r = .252, p = .024) independently explaining 6.8% and 5.1% of the variance respectively. Gender independently explained 5.6% of the variance in nutrition knowledge (p= .017) and 6.7% in total A-ARFS (p = .016). Higher nutrition knowledge and female gender were weakly but positively associated with better diet quality. Given the importance of nutrition to health and optimal sports performance, intervention to improve nutrition knowledge and healthy eating is recommended, especially for young male athletes.

A systematic review and metaanalysis of energy intake and weight gain in pregnancy.

BACKGROUND Gestational weight gain within the recommended range produces optimal pregnancy outcomes, yet many women exceed the guidelines. Official recommendations to increase energy intake by ∼ 1000 kJ/day in pregnancy may be excessive. OBJECTIVE To determine by metaanalysis of relevant studies whether greater increments in energy intake from early to late pregnancy corresponded to greater or excessive gestational weight gain. DATA SOURCES We systematically searched electronic databases for observational and intervention studies published from 1990 to the present. The databases included Ovid Medline, Cochrane Library, Excerpta Medica DataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Science Direct. In addition we hand-searched reference lists of all identified articles. STUDY ELIGIBILITY CRITERIA Studies were included if they reported gestational weight gain and energy intake in early and late gestation in women of any age with a singleton pregnancy. Search also encompassed journals emerging from both developed and developing countries. STUDY APPRAISAL AND SYNTHESIS METHODS Studies were individually assessed for quality based on the Quality Criteria Checklist obtained from the Evidence Analysis Manual: Steps in the academy evidence analysis process. Publication bias was plotted by the use of a funnel plot with standard mean difference against standard error. Identified studies were meta-analyzed and stratified by body mass index, study design, dietary methodology, and country status (developed/developing) by the use of a random-effects model. RESULTS Of 2487 articles screened, 18 studies met inclusion criteria. On average, women gained 12.0 (2.8) kg (standardized mean difference = 1.306, P < .0005) yet reported only a small increment in energy intake that did not reach statistical significance (∼475 kJ/day, standard mean difference = 0.266, P = .016). Irrespective of baseline body mass index, study design, dietary methodology, or country status, changes in energy intake were not significantly correlated to the amount of gestational weight gain (r = 0.321, P = .11). CONCLUSION Despite rapid physiologic weight gain, women report little or no change in energy intake during pregnancy. Current recommendations to increase energy intake by ∼ 1000 kJ/day may, therefore, encourage excessive weight gain and adverse pregnancy outcomes.

Psychometric properties of the children's revised impact of events scale (CRIES) with Bangladeshi children and adolescents

Identification of possible cases suffering post-traumatic stress disorder (PTSD) is important, especially in developing countries where traumatic events are typically prevalent. The Children’s Revised Impact of Events Scale is a reliable and valid measure that has two brief versions (13 items and 8 items) to assess reactions to traumatic events among young people. The current study evaluated the psychometric properties of both versions of the CRIES in a sample of 1,342 children and adolescents aged 9–17 years (M = 12.3 years, SD = 2.12) recruited from six districts of Bangladesh. A sub-group of 120 children from four schools was re-tested on the measures within 3.5 weeks. Confirmatory factor analysis supported factor structures similar to those found in other studies for both versions of the CRIES. Multiple group confirmatory factor analysis showed gender and age-group differences within the sample, supporting established age and gender differences in prevalence of PTSD symptoms. Analyses also indicated moderate to excellent internal consistency and test-retest reliability and clear discriminant and convergent validity. These data support use of both the CRIES-13 and CRIES-8 to provide quick and psychometrically sound assessment of symptoms of PTSD among children and adolescents from Bangla-speaking communities.

Numerical algorithms for constrained maximum likelihood estimation

This paper describes a SQP-type algorithm for solving a constrained maximum likelihood estimation problem that incorporates a number of novel features. We call it MLESOL. MLESOL maintains the use of an estimate of the Fisher information matrix to the Hessian of the negative log-likelihood but also encompasses a secant approximation S to the second-order part of the augmented Lagrangian function along with tests for when to use this information. The local quadratic model used has a form something like that of Tapias SQP augmented scale BFGS secant method but explores the additional structure of the objective function. The step choice algorithm is based on minimising a local quadratic model subject to the linearised constraints and an elliptical trust region centred at the current approximate minimiser. This is accomplished using the Byrd and Omojokun trust region approach, together with a special module for assessing the quality of the step thus computed. The numerical performance of MLESOL is studied by means of an example involving the estimation of a mixture density.

Evaluation of General Nutrition Knowledge in Australian Military Personnel

BACKGROUND Sound nutrition knowledge and a balanced diet are essential for operational readiness and optimal health of military personnel. Few studies have examined nutrition knowledge in this population. OBJECTIVE To assess the level of general nutrition knowledge across military occupations (ie, officers [OFFRs], physical training instructors [PTIs], cooks [CKs], and soldiers [SOLs]) compared with a civilian, community (C) sample. DESIGN Cross-sectional study. PARTICIPANTS/SETTING Convenience sample of Australian military (M) and C participants. MAIN OUTCOME MEASURES General nutrition knowledge measured using the validated General Nutrition Knowledge Questionnaire (GNKQ). Knowledge scores and the influence of demographic characteristics (eg, age, sex, level of education, and living arrangement) within and between M and C groups were evaluated. STATISTICAL ANALYSES Analysis of variance, general linear models, independent-samples median test, t tests, χ(2) test, and Spearmans correlation. RESULTS A sample of 1,295 participants were recruited with 622 (48%) from C. The M sample (n=673) consisted of SOLs 62.1%, OFFRs 9.1%, PTIs 12.8%, and CKs 16.0%. Mean age was higher for C than M (35.5±14 y vs 29.7±9.2 y; P<0.001). However, SOLs were younger and OFFRs older than other groups (P<0.001). The M sample had more men (91.1% vs 39.4%; P<0.001). The OFFRs, PTIs, and C members had similar total GNKQ scores (62.8%, 61.9%, and 64.7%, respectively) with these groups higher (P<0.001) than CKs and SOLs (56.4% and 50.6%, respectively). Across all participants, there was a positive relationship between total GNKQ score and age, female sex, and tertiary education (all P values <0.001). Significant differences identified in total GNKQ score between groups remained after adjusting for demographic factors. Young men (M or C) without tertiary education had the lowest GNKQ scores. CONCLUSIONS Because low general nutrition knowledge may be detrimental to dietary intake, health, and operational readiness in military personnel, nutrition education programs particularly targeted at SOLs and CKs seem warranted.

Adaptive algorithm for constrained least-squares problems

This paper is concerned with the implementation and testing of an algorithm for solving constrained least-squares problems. The algorithm is an adaptation to the least-squares case of sequential quadratic programming (SQP) trust-region methods for solving general constrained optimization problems. At each iteration, our local quadratic subproblem includes the use of the Gauss–Newton approximation but also encompasses a structured secant approximation along with tests of when to use this approximation. This method has been tested on a selection of standard problems. The results indicate that, for least-squares problems, the approach taken here is a viable alternative to standard general optimization methods such as the Byrd–Omojokun trust-region method and the Powell damped BFGS line search method.

Relationship between general nutrition knowledge and diet quality in Australian military personnel.

A balanced diet informed by sound nutrition knowledge is key for operational readiness and the health of military personnel. Unfortunately, research suggests that military personnel have inadequate dietary intakes. This study assessed general nutrition knowledge, diet quality and their association in Australian military personnel. A convenience sample of male military personnel (n 211) including Army soldiers and officers completed a validated general nutrition knowledge questionnaire (GNKQ) and FFQ. The GNKQ assessed knowledge of dietary guidelines (Section A), sources of nutrients (Section B), choosing everyday foods (Section C) and diet-disease relationships (Section D). The Australian Recommended Food Score (ARFS) was used to assess diet quality from FFQ data. Statistical analyses included the χ 2 test, Spearmans correlation test, t test, median test, ANCOVA and ordinal logistic regression. The mean total GNKQ score was 52·7 %. Participants performed best on Section A (58·5 %) followed by Sections B (57·3 %) and C (57·0 %) and worst on Section D (31·0 %). Overall, officers scored significantly higher than soldiers (58·7 v. 51·9 %, P=0·001). Age was weakly but positively correlated with GNKQ total scores (r 0·307; P<0·0005), with no significant effects seen for level of education (P=0·463) or living arrangement (P=0·167). Overall ARFS was 37·6 (sd 7·7) (50·8 %) with officers scoring significantly higher than soldiers (54·7 v. 50·3 %, P=0·040). No demographic variables influenced total ARFS. The total GNKQ score had a significant, positive but weak relationship with total ARFS (r 0·179; P=0·009). Given the importance of nutrition to personnel health and operational readiness, initiatives to improve nutrition knowledge and diet quality are recommended in this population, especially in soldiers.