Tim Olds
Biographic Data
| ID | 85072 |
|---|---|
| NAME | Tim Olds |
| GIVEN NAMES | Tim |
| FAMILY NAME | Olds |
| SIGNATURE | OLDS T |
| AFFILIATIONS | University of South Australia |
| ORCID | 0000-0001-6894-5519 |
| VERIFIED | Yes |
| TOTAL WORKS | 61 |
| TOTAL CITATIONS | 52 |
| AUTHOR COUNT | 61 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1996 |
| LATEST PUBLICATION YEAR | 2025 |
| H-INDEX | 5 |
Levelling-up summer: Using summer holiday programs to support child health and wellbeing – a Delphi study
There is clear stakeholder support for expanding structured summer holiday programming in Australia, particularly to benefit children from disadvantaged backgrounds. Programs have the potential to promote health, wellbeing, and equity, but realising this will require government investment, local partnerships, and delivery models that reflect community needs. These findings may inform similar efforts in other countries where summer programs are no…
‘He wants to play football but not available here … ’ Parent perspectives of Aboriginal and Torres Strait Islander child physical activity and sport participation
Aboriginal and Torres Strait Islander children have higher physical activity participation levels than non-Aboriginal children. However, this trend reverses in adulthood. Data came from the Longitudinal Study of Indigenous Children (LSIC) at age 8–13 years. Using conventional content analysis, interviews with primary caregivers of Aboriginal and Torres Strait Islander children were analyzed to understand current sports and physical activity parti…
Changes in fitness and fatness in Australian schoolchildren during the summer holidays: Fitness lost, fatness regained? A cohort study
Australia New Zealand Clinical Trials Registry, identifier ACTRN12618002008202. Retrospectively registered on 14 December 2018
Association between the use of weight management strategies and weight change among Australian adults over 12 months: An observational study
The use of weight management strategies appears to be common. Being physically active was associated with greater weight loss. Individuals who accepted their current body weight were less likely to use weight management strategies. Fasting and the use of supplements were associated with poorer mental health. Promoting physical activity as a weight management strategy appears important, particularly considering its multiple health benefits
Goldilocks Days: Optimising children’s time use for health and well-being
BACKGROUND: One size rarely fits all in population health. Differing outcomes may compete for best allocations of time. Among children aged 11-12 years, we aimed to (1) describe optimal 24-hour time use for diverse physical, cognitive/academic and well-being outcomes, (2) pinpoint the 'Goldilocks Day' that optimises all outcomes and (3) develop a tool to customise time-use recommendations. METHODS: In 2004, the Longitudinal Study of Australian Ch…
Sport and academic performance in Australian Indigenous children
Objective Sport may promote academic performance through physiological and psychosocial mechanisms. We aimed to examine the association between sports participation and academic performance in Aboriginal and Torres Strait Islander children. Methods Participants were from four successive waves of Australia’s Longitudinal Study of Indigenous Children ( n = 303, baseline age 5–6 y). Cumulative sports participation was regressed against academic perf…
Examining social-cognitive theory constructs as mediators of behaviour change in the active team smartphone physical activity program: A mediation analysis
This trial was registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12617000113358 , date of registration 23 January, 2017)
Annual rhythms in adults’ lifestyle and health (Aria): Protocol for a 12-month longitudinal study examining temporal patterns in weight, activity, diet, and wellbeing in Australian adults
Australia New Zealand Clinical Trials Registry, identifier ACTRN12619001430123 . Prospectively registered on 16 October 2019
Are all MVPA minutes equal? Associations between MVPA characteristics, independent of duration, and childhood adiposity
Characteristics of MVPA other than duration and intensity appear to be unrelated to adiposity
Associations Between 24-Hour Time Use and Academic Achievement in Australian Primary School–Aged Children
Background Previous research has examined associations between individual activity behaviors and academic achievement. Yet activity behaviors should be analyzed together because they are codependent parts of the 24-hour day. Aims This study aims to explore the associations between all daily activity behaviors (sleep, sedentary time, light physical activity [LPA], and moderate-to-vigorous physical activity [MVPA]) and academic achievement using co…
Lifestyle clusters and academic achievement in Australian Indigenous children: Empirical findings and discussion of ecological levers for closing the gap
Participation in sport and physical activity can improve academic outcomes and has been identified as a potential mechanism for addressing educational disadvantage and 'closing the gap' in Australian Indigenous communities. To explore this possibility in relation to sport and lifestyle we performed a cluster analysis on data from the Footprints in Time study (also known as the Longitudinal Study of Indigenous Children), using data from Waves 3-6 …
Breastfeeding and childhood obesity: A 12‐country study
This study aimed to examine the association between breastfeeding and childhood obesity. A multinational cross-sectional study of 4,740 children aged 9-11 years was conducted from 12 countries. Infant breastfeeding was recalled by parents or legal guardians. Height, weight, waist circumference, and body fat were obtained using standardized methods. The overall prevalence of obesity, central obesity, and high body fat were 12.3%, 9.9%, and 8.1%, r…
Compositional Data Analysis in Time-Use Epidemiology: What, Why, How
In recent years, the focus of activity behavior research has shifted away from univariate paradigms (e.g., physical activity, sedentary behavior and sleep) to a 24-h time-use paradigm that integrates all daily activity behaviors. Behaviors are analyzed relative to each other, rather than as individual entities. Compositional data analysis (CoDA) is increasingly used for the analysis of time-use data because it is intended for data that convey rel…
Children's sleep and health: A meta-review
It’s not raining men: A mixed-methods study investigating methods of improving male recruitment to health behaviour research
Evidence-based approaches can improve Facebook recruitment outcomes, however, there are complex barriers hindering male recruitment to health behaviour studies that may necessitate multi-faceted strategies including involvement of family and friends
Association between breakfast frequency and physical activity and sedentary time: A cross-sectional study in children from 12 countries
The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) is registered at (Identifier NCT01722500 )
Life on holidays: Differences in activity composition between school and holiday periods in Australian children
In this subsample of a nationally representative survey of Australian children, holidays were characterised by longer sleep and higher TV and videogame time, lower vigorous activity and lower TDEE. Uncompensated by dietary adjustments, these differences would result in an accumulation of about 650 g of fat over a six-week holiday period. Holiday activity patterns may be a promising focus for obesity prevention efforts
Use of previous-day recalls of physical activity and sedentary behavior in epidemiologic studies: Results from four instruments
Although there were many similarities between instruments, differences in operationalizing definitions of sedentary behaviour and LPA resulted in substantive differences in the amounts of time reported in sedentary and physically active behaviours. Future research should focus on deriving a core set of basic activities and associated energy expenditure estimates, an agreed classificatory hierarchy for the major behavioural and activity domains, a…
Changes in weight status, quality of life and behaviours of South Australian primary school children: Results from the Obesity Prevention and Lifestyle (Opal) community intervention program
ACTRN12616000477426 (12th April 2016, retrospectively registered)
Life on holidays: Study protocol for a 3-year longitudinal study tracking changes in children’s fitness and fatness during the in-school versus summer holiday period
Australia New Zealand Clinical Trials Registry, identifier ACTRN12618002008202 . Retrospectively registered on 14 December 2018
Compositional data analysis for physical activity, sedentary time and sleep research
The health effects of daily activity behaviours (physical activity, sedentary time and sleep) are widely studied. While previous research has largely examined activity behaviours in isolation, recent studies have adjusted for multiple behaviours. However, the inclusion of all activity behaviours in traditional multivariate analyses has not been possible due to the perfect multicollinearity of 24-h time budget data. The ensuing lack of adjustment …
Patterns of Time Use across the Chronic Obstructive Pulmonary Disease Severity Spectrum
Descriptions of time use patterns in people with chronic obstructive pulmonary disease (COPD) are scarce and the relationship between use-of-time and COPD severity remains unclear. This study aimed to describe a typical day for people with COPD and to explore the differences in time-use patterns across the Body Mass-Index, Airflow Obstruction, Dyspnoea and Exercise Capacity (BODE) index using compositional analyses. Using a cross-sectional design…
Adiposity and the isotemporal substitution of physical activity, sedentary time and sleep among school-aged children: A compositional data analysis approach
The compositional isotemporal model caters for the constrained and therefore relative nature of activity behaviour data and enables all daily behaviours to be included in a single statistical model. The traditional model treats data as real variables, thus the constrained nature of time is not accounted for, nor reflected in the findings. Findings from compositional isotemporal substitution support the importance of MVPA to children's health, and…
Human development index, children’s health-related quality of life and movement behaviors: A compositional data analysis
Sleep patterns and sugar-sweetened beverage consumption among children from around the world
Objective To examine the relationships between objectively measured sleep patterns (sleep duration, sleep efficiency and bedtime) and sugar-sweetened beverage (SSB) consumption (regular soft drinks, energy drinks, sports drinks and fruit juice) among children from all inhabited continents of the world. Design Multinational, cross-sectional study. Setting The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Subject…
Relationship between adiposity and body size reveals limitations of BMI
The aims of this study were to assess 1) whether the stature-adjusted body mass index (BMI) is a valid proxy for adiposity across both athletic and nonathletic populations, and 2) whether skinfold measurements increase in proportion to body size, thus obeying the principle of geometric similarity. The research design was cross-sectional, allowing the relationship between skinfold calliper readings (at eight sites and between specific athletic and…
Ken and Barbie at life size
The effects of gender, motor skills and play area on the free play activities of 8–11 year old school children
Are adult physiques geometrically similar? The dangers of allometric scaling using body mass power laws
Human physique classification by somatotype assumes that adult humans are geometric similar to each other. However, this assumption has yet to be adequately tested in athletic and nonexercising human populations. In this study, we assessed this assumption by comparing the mass exponents associated with girth measurements taken at 13 different sites throughout the body in 478 subjects (279 athletic subjects, and 199 nonexercising controls). Correc…
One Hundred Years of Growth: The Evolution of Height, Mass, and Body Composition in Australian Children, 1899-1999
This paper summarizes 41 reports on the height and mass of Australian children aged between 5.00 and 16.99 years between 1899 and 1999. In all, data on 644,613 children were collated, including individual data on 68,196 children. After primary data treatment to correct for methodological and statistical artifacts, regressions were calculated to quantify the rate of change of height and mass over time. Distributional analysis was used to probe for…
"Don't eat that, you'll get fat!" Exploring how parents and children conceptualise and frame messages about the causes and consequences of obesity
Physical activity among indigenous Australian children and youth in remote and non-remote areas
Associations of neighborhood social environment attributes and physical activity among 9–11 year old children from 12 countries
Minutes, MET minutes, and METs: Unpacking socio-economic gradients in physical activity in adolescents
BACKGROUND: There is conflicting evidence regarding the relationship between socio-economic position (SEP) and physical activity in adolescents. The aim of this study was to investigate associations between SEP and characteristics of physical activity in Australian adolescents using a high-resolution use-of-time tool. METHOD: Use-of-time and pedometer data were collected on a random sample of 2071 9-16-year-old Australian children. Use-of-time wa…
Goldilocks Days: Optimising children’s time use for health and well-being
BACKGROUND: One size rarely fits all in population health. Differing outcomes may compete for best allocations of time. Among children aged 11-12 years, we aimed to (1) describe optimal 24-hour time use for diverse physical, cognitive/academic and well-being outcomes, (2) pinpoint the 'Goldilocks Day' that optimises all outcomes and (3) develop a tool to customise time-use recommendations. METHODS: In 2004, the Longitudinal Study of Australian Ch…
Technical note: Criterion validity of whole body surface area equations: A comparison using 3D laser scanning
Measurements of whole body surface area (WBSA) have important applications in numerous fields including biological anthropology, clinical medicine, biomechanics, and sports science. Currently, WBSA is most often estimated using predictive equations due to the complex and time consuming methods required for direct measurement. The main aim of this study was to identify whether there were significant and meaningful differences between WBSA measurem…
Ken and Barbie at life size
One Hundred Years of Growth: The Evolution of Height, Mass, and Body Composition in Australian Children, 1899-1999
This paper summarizes 41 reports on the height and mass of Australian children aged between 5.00 and 16.99 years between 1899 and 1999. In all, data on 644,613 children were collated, including individual data on 68,196 children. After primary data treatment to correct for methodological and statistical artifacts, regressions were calculated to quantify the rate of change of height and mass over time. Distributional analysis was used to probe for…
Are adult physiques geometrically similar? The dangers of allometric scaling using body mass power laws
Human physique classification by somatotype assumes that adult humans are geometric similar to each other. However, this assumption has yet to be adequately tested in athletic and nonexercising human populations. In this study, we assessed this assumption by comparing the mass exponents associated with girth measurements taken at 13 different sites throughout the body in 478 subjects (279 athletic subjects, and 199 nonexercising controls). Correc…
Relationship between adiposity and body size reveals limitations of BMI
The aims of this study were to assess 1) whether the stature-adjusted body mass index (BMI) is a valid proxy for adiposity across both athletic and nonathletic populations, and 2) whether skinfold measurements increase in proportion to body size, thus obeying the principle of geometric similarity. The research design was cross-sectional, allowing the relationship between skinfold calliper readings (at eight sites and between specific athletic and…
The effects of gender, motor skills and play area on the free play activities of 8–11 year old school children
Development of a Compendium of Energy Expenditures for Youth.
BACKGROUND: This paper presents a Compendium of Energy Expenditures for use in scoring physical activity questionnaires and estimating energy expenditure levels in youth. METHOD/RESULTS: Modeled after the adult Compendium of Physical Activities, the Compendium of Energy Expenditures for Youth contains a list of over 200 activities commonly performed by youth and their associated MET intensity levels. A review of existing data collected on the ene…
Health-related quality of life in obese children and adolescents
How many steps/day are enough? for children and adolescents
Worldwide, public health physical activity guidelines include special emphasis on populations of children (typically 6-11 years) and adolescents (typically 12-19 years). Existing guidelines are commonly expressed in terms of frequency, time, and intensity of behaviour. However, the simple step output from both accelerometers and pedometers is gaining increased credibility in research and practice as a reasonable approximation of daily ambulatory …
Evidence that the prevalence of childhood overweight is plateauing: Data from nine countries
Until quite recently, there has been a widespread belief in the popular media and scientific literature that the prevalence of childhood obesity is rapidly increasing. However, high quality evidence has emerged from several countries suggesting that the rise in the prevalence has slowed appreciably, or even plateaued. This review brings together such data from nine countries (Australia, China, England, France, Netherlands, New Zealand, Sweden, Sw…
Minutes, MET minutes, and METs: Unpacking socio-economic gradients in physical activity in adolescents
BACKGROUND: There is conflicting evidence regarding the relationship between socio-economic position (SEP) and physical activity in adolescents. The aim of this study was to investigate associations between SEP and characteristics of physical activity in Australian adolescents using a high-resolution use-of-time tool. METHOD: Use-of-time and pedometer data were collected on a random sample of 2071 9-16-year-old Australian children. Use-of-time wa…
In search of lost sleep: Secular trends in the sleep time of school-aged children and adolescents
A negative relationship between leg length and leg cross‐sectional areas in adults
OBJECTIVES: These were to examine the relationship between leg cross-sectional areas (CSAs) and leg length while making allowance for other factors, such as fatness and the load on the legs. METHODS: Body mass, stature, and sitting height were directly measured and volumes and leg CSAs were obtained by 3D scanning for 155 men and 162 women. Leg CSAs were regressed simultaneously on upper body mass and leg length. RESULTS: With allowance made for …
Testing the activitystat hypothesis: A randomised controlled trial protocol
Australian New Zealand Clinical Trials Registry ACTRN12610000248066
Rationale, design and methods for a staggered-entry, waitlist controlled clinical trial of the impact of a community-based, family-centred, multidisciplinary program focussed on activity, food and att…
Australian New Zealand Clinical Trials Registry ACTRN12611001187932
Technical note: Criterion validity of whole body surface area equations: A comparison using 3D laser scanning
Measurements of whole body surface area (WBSA) have important applications in numerous fields including biological anthropology, clinical medicine, biomechanics, and sports science. Currently, WBSA is most often estimated using predictive equations due to the complex and time consuming methods required for direct measurement. The main aim of this study was to identify whether there were significant and meaningful differences between WBSA measurem…
Volumetric differences in body shape among adults with differing body mass index values: An analysis using three‐dimensional body scans
Body shape changes due to variations in body volume could have important implications in a range of fields that currently use 1D anthropometric measurements that do not capture body shape differences in the same detail
Effectiveness of a facebook-delivered physical activity intervention for post-partum women: A randomized controlled trial protocol
Australia and New Zealand Clinical Trials Register: ACTRN12613000069752
The International Study of Childhood Obesity, Lifestyle and the Environment (Iscole): Design and methods
The results of this study will provide a robust examination of the correlates of adiposity and obesity in children, focusing on both sides of the energy balance equation. The results will also provide important new information that will inform the development of lifestyle, environmental, and policy interventions to address and prevent childhood obesity that may be culturally adapted for implementation around the world. ISCOLE represents a multi-n…
Changes in use of time, activity patterns, and health and wellbeing across retirement: Design and methods of the life after work study
The results will provide important new information that will inform the development of lifestyle and policy interventions to address and improve health and well-being in retirement
Screen-based media use clusters are related to other activity behaviours and health indicators in adolescents
SBM use by adolescents did cluster and these clusters related differently to activity/sedentary behaviours and both physical and psychosocial health indicators. It is clear that SBM use is not a single construct and future research needs to take consideration of this if it intends to understand the impact SBM has on health
Statistical approaches to relationships between sitting height and leg length in adults
The linear equations suggest that LL tends to vary in proportion to SH minus a quantity similar to head height. A new index of relative LL may therefore be preferable to the CI for some research purposes to reflect this, but there is otherwise no strong reason to abandon the use of the CI
Development and psychometric properties of the Y-Pass questionnaire to assess correlates of lunchtime and after-school physical activity in children
The preliminary reliability and factorial structure evidence suggests the Y-PASS correlate questionnaires are robust tools for measuring correlates of context-specific physical activity in children. The multi-dimensional factor structure provides justification for exploring physical activity correlates from a social ecological perspective and demonstrates the importance of developing items that are context specific. Further development and refine…
Parent and child interactions with two contrasting anti-obesity advertising campaigns: A qualitative analysis
Well-funded, targeted social marketing campaigns will play an important role in the prevention and management of obesity. It is important that these campaigns are comprehensively evaluated and are backed up with structural supports to enable and encourage population subgroups to act upon messages
"Don't eat that, you'll get fat!" Exploring how parents and children conceptualise and frame messages about the causes and consequences of obesity
Proportion of children meeting recommendations for 24-hour movement guidelines and associations with adiposity in a 12-country study
BACKGROUND: The Canadian 24-h movement guidelines were developed with the hope of improving health and future health outcomes in children and youth. The purpose of this study was to evaluate adherence to the 3 recommendations most strongly associated with health outcomes in new 24-h movement guidelines and their relationship with adiposity (obesity and body mass index z-score) across countries participating in the International Study of Childhood…
Medicine (59 works) · Obesity, Physical Activity, Diet (42 works) · Physical therapy (30 works) · Demography (28 works) · Physical activity (25 works) · Physical Activity and Health (24 works) · Biostatistics (22 works) · Gerontology (21 works) · Psychology (21 works) · Public health (21 works)