Margaret Allman-Farinelli

Age, period and birth cohort effects on prevalence of overweight and obesity in Australian adults from 1990 to 2000

Objective:To assess the individual contributions of age, period and birth cohort to prevalence of overweight and obesity in the Australian population during 1990 to 2000.Design:Age-period-cohort Poisson regression modelling of data from National Health Surveys conducted in Australia in 1990, 1995 and 2000.Subjects:Adults aged 20 years and over. Weightings were applied to account for differences in sampling and participation rates so that the sample is representative of the entire Australian adult population.Methods:Twelve age groups, based on 5-year intervals from 20 to 24 years to greater than 75 years, three survey periods and 14 cohorts, also based on 5-year intervals from pre-1915 up to 1976–1980, were used in the analysis. The data were age-standardized to the 2000 population and body mass index (BMI) was calculated. Log-linear models, for the prevalence rates of overall overweight (BMI ⩾25) and of obesity (BMI ⩾30) were fitted to the data.Results:Age (P<0.001), period (P<0.001) and cohort (P=0.002) all showed significant independent effects on prevalence of overall overweight in the Australian population such that prevalence rises with increasing age, recency of period and cohorts born since 1960. Age (P<0.001) and period (P<0.001) demonstrated strong effects on prevalence of obesity but birth cohort (P=0.07) was not significant. The effects were similar for men and women except that the overall effect of birth cohort on overall overweight was significant in women (P<0.05) but not men (P=0.09).Conclusion:The prevalence of overweight and obesity in Australian adults continued to rise during the 1990s. The obesogenic environment seems to have worsened and more recently born cohorts may be at increased risk of overweight.

Development of Smartphone Applications for Nutrition and Physical Activity Behavior Change

Background Young adults (aged 18 to 35) are a population group at high risk for weight gain, yet we know little about how to intervene in this group. Easy access to treatment and support with self-monitoring of their behaviors may be important. Smartphones are gaining in popularity with this population group and software applications (“apps”) used on these mobile devices are a novel technology that can be used to deliver brief health behavior change interventions directly to individuals en masse, with potentially favorable cost-utility. However, existing apps for modifying nutrition or physical activity behaviors may not always reflect best practice guidelines for weight management. Objective This paper describes the process of developing four apps aimed at modifying key lifestyle behaviors associated with weight gain during young adulthood, including physical activity, and consumption of take-out foods (fast food), fruit and vegetables, and sugar-sweetened drinks. Methods The development process involved: (1) deciding on the behavior change strategies, relevant guidelines, graphic design, and potential data collection; (2) selecting the platform (Web-based versus native); (3) creating the design, which required decisions about the user interface, architecture of the relational database, and programming code; and (4) testing the prototype versions with the target audience (young adults aged 18 to 35). Results The four apps took 18 months to develop, involving the fields of marketing, nutrition and dietetics, physical activity, and information technology. Ten subjects provided qualitative feedback about using the apps. The slow running speed of the apps (due to a reliance on an active Internet connection) was the primary issue identified by this group, as well as the requirement to log in to the apps. Conclusions Smartphone apps may be an innovative medium for delivering individual health behavior change intervention en masse, but researchers must give consideration to the target population, available technologies, existing commercial apps, and the possibility that their use will be irregular and short-lived.

Obesity and Venous Thrombosis: A Review

The world is experiencing an obesity pandemic, with rates of obesity rising for more than two decades. Obesity is defined as a body mass index (BMI) of 30 kg/m (2) or greater. Of particular concern are the risks that millions of obese people are likely to develop chronic diseases and at earlier ages than their parents might have. The risk of venous thrombosis increases with obesity, so that the incidence of this pathology is also expected to rise significantly. There is remarkable and consistent evidence from a systematic review, as well as cohort and case-control studies that obesity might predispose to venous thromboembolism (VTE). The risk appears to be at least double that for normal weight subjects (BMI 20 to 24.9 kg/m (2)). Plausible mechanisms exist to explain this relationship, including the physical effects of body fat limiting venous return and a proinflammatory, prothrombotic, and hypofibrinolytic milieu. Loss of body weight has been shown to reduce the concentrations of coagulation factors and plasminogen activator inhibitor-1 toward the normal range. Whether weight loss would prevent secondary occurrence of VTE in the absence of anticoagulant therapy could not be discerned from this literature search.

Leisure-time physical activity alone may not be a sufficient public health approach to prevent obesity - a focus on China.

Much small‐scale research has identified the role of physical activity in obesity prevention. This is the ‘energy expenditure’ side of the energy balance equation. Although around half an hour of daily moderate‐intensity physical activity is required for cardiovascular health and disease prevention, the quantum of physical activity required for obesity prevention and weight loss is around 60–90 minutes per day. This amount of physical activity is difficult to achieve through leisure time physical activity (LTPA) alone, and additional energy expenditure is needed in the domains of active transport, occupation activity and in domestic settings. Modeling of 24‐hour energy expenditures demonstrate the need for ‘active living’, namely energy expenditure over and above that due to LTPA, for weight loss and obesity prevention. The consequences of this for developing countries such as China are the need to focus on preventing the declines in energy expenditure attributable to urbanization, industrialization, and motor vehicle dependence. These will pose policy challenges in the developing world, if they are to be taken seriously as obesity prevention strategies.

The Most Popular Smartphone Apps for Weight Loss: A Quality Assessment

Background Advancements in mobile phone technology have led to the development of smartphones with the capability to run apps. The availability of a plethora of health- and fitness-related smartphone apps has the potential, both on a clinical and public health level, to facilitate healthy behavior change and weight management. However, current top-rated apps in this area have not been extensively evaluated in terms of scientific quality and behavioral theory evidence base. Objective The purpose of this study was to evaluate the quality of the most popular dietary weight-loss smartphone apps on the commercial market using comprehensive quality assessment criteria, and to quantify the behavior change techniques (BCTs) incorporated. Methods The top 200-rated Health & Fitness category apps from the free and paid sections of Google Play and iTunes App Store in Australia (n=800) were screened in August 2014. To be included in further analysis, an app had to focus on weight management, include a facility to record diet intake (self-monitoring), and be in English. One researcher downloaded and used the eligible apps thoroughly for 5 days and assessed the apps against quality assessment criteria which included the following domains: accountability, scientific coverage and content accuracy of information relevant to weight management, technology-enhanced features, usability, and incorporation of BCTs. For inter-rater reliability purposes, a second assessor provided ratings on 30% of the apps. The accuracy of app energy intake calculations was further investigated by comparison with results from a 3-day weighed food record (WFR). Results Across the eligible apps reviewed (n=28), only 1 app (4%) received full marks for accountability. Overall, apps included an average of 5.1 (SD 2.3) out of 14 technology-enhanced features, and received a mean score of 13.5 (SD 3.7) out of 20 for usability. The majority of apps provided estimated energy requirements (24/28, 86%) and used a food database to calculate energy intake (21/28, 75%). When compared against the WFR, the mean absolute energy difference of apps which featured energy intake calculations (23/28, 82%) was 127 kJ (95% CI -45 to 299). An average of 6.3 (SD 3.7) of 26 BCTs were included. Conclusions Overall, the most popular commercial apps for weight management are suboptimal in quality, given the inadequate scientific coverage and accuracy of weight-related information, and the relative absence of BCTs across the apps reviewed. With the limited regulatory oversight around the quality of these types of apps, this evaluation provides clinicians and consumers an informed view of the highest-quality apps in the current popular app pool appropriate for recommendation and uptake. Further research is necessary to assess the effectiveness of apps for weight management.

Lifestyle intervention for preventing weight gain in young adults: a systematic review and meta‐analysis of RCTs

Younger generations of Australians are gaining weight faster than their parents. Associated health consequences are likely to ensue unless weight gains are prevented; however, it is unclear how to effectively intervene in this population. Electronic databases for health sciences were searched from April to the end of August 2011. Nine studies were included in the review, eight in the meta‐analysis, from 771 abstracts reviewed for eligibility criteria: randomized controlled trials of lifestyle interventions, published in English (1980 onward), aimed at preventing weight gain among healthy subjects 18–35 years. Mean body weight change was the primary outcome. The combined weighted mean change in intervention participants was −0.87 kg (95% CI −1.56, −0.18) and in control participants 0.86 kg (95% CI 0.14, 1.57). Post hoc meta‐regression analyses revealed evidence‐based interventions of 4 months or longer duration were significantly associated with greater weight loss (−1.62 [95% CI −3.21, −0.04], P = 0.045). The small number, short duration and large heterogeneity of trials means the effectiveness of lifestyle intervention for preventing young adult weight gain remains unclear. Future trials conducted over longer periods with larger samples are urgently required to develop effective programmes that will protect against weight gains in future generations.

A systematic review and meta‐analysis of interventions for weight management using text messaging

BACKGROUND Obesity prevalence continues to increase worldwide, with significant associated chronic disease and health cost implications. Among more recent innovations in health service provision is the use of text messaging for health behaviour change interventions including weight management. This review investigates the efficacy of weight management programmes incorporating text messaging. METHODS Medical and scientific databases were searched from January 1993 to October 2013. Eligibility criteria included randomised controlled trials (RCTs), pseudoRCTs and before and after studies of weight management, among healthy children and adults, that used text messaging and included a nutrition component. Data extraction and quality assessment followed guidelines from PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) and the Evidence Analysis Manual of the American Academy of Nutrition and Dietetics. RESULTS From 512 manuscripts retrieved, 14 met the inclusion criteria (five manuscripts in children and nine in adults). Duration of interventions ranged from 1 to 24 months. Frequency of text messaging was from daily to fortnightly. Six studies in adults were included in a meta-analysis with mean body weight change as the primary outcome. The weighted mean change in body weight in intervention participants was -2.56 kg (95% confidence interval = -3.46 to -1.65) and in controls -0.37 kg (95% confidence interval = -1.22 to 0.48). CONCLUSIONS The small body of evidence indicates that text messaging interventions can promote weight loss. However, lack of long-term results indicate that further efficacy studies are required. Future investigations should elucidate the determinants, such as intervention duration, text message frequency and level of interactivity that maximise the success and cost effectiveness of the delivery medium.

‘TXT2BFiT’ a mobile phone-based healthy lifestyle program for preventing unhealthy weight gain in young adults: study protocol for a randomized controlled trial

BackgroundDespite international efforts to arrest increasing rates of overweight and obesity, many population strategies have neglected young adults as a target group. Young adults are at high risk for unhealthy weight gain which tends to persist throughout adulthood with associated chronic disease health risks.Methods/designTXT2BFiT is a nine month two-arm parallel-group randomized controlled trial aimed at improving weight management and weight-related dietary and physical activity behaviors among young adults. Participants are recruited via general practice (primary medical care) clinics in Sydney, New South Wales, Australia. All participants receive a mailed resource outlining national physical activity and dietary guidelines and access to the study website. Additional resources accessible to the intervention arm via the study website include Smartphone mobile applications, printable handouts, an interactive healthy weight tracker chart, and a community blog. The study consists of two phases: (1) Intensive phase (weeks 1 to 12): the control arm receives four short message service (SMS) text messages; the intervention arm receives eight SMS messages/week tailored to their baseline stage-of-change, one Email/week, and personalized coaching calls during weeks 0, 2, 5, 8, and 11; and (2) Maintenance phase (weeks 14 to 36): the intervention arm receives one SMS message/month, one Email/month and booster coaching calls during months 5 and 8. A sample of N = 354 (177 per arm) is required to detect differences in primary outcomes: body weight (kg) and body mass index (kg/m2), and secondary outcomes: physical activity, sitting time, intake of specific foods, beverages and nutrients, stage-of-change, self-efficacy and participant well-being, at three and nine months. Program reach, costs, implementation and participant engagement will also be assessed.DiscussionThis mobile phone based program addresses an important gap in obesity prevention efforts to date. The method of intervention delivery is via platforms that are highly accessible and appropriate for this population group. If effective, further translational research will be required to assess how this program might operate in the broader community.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12612000924853

Vitamin B12 status, cognitive decline and dementia: a systematic review of prospective cohort studies

Poor vitamin B₁₂ status may lead to the development of cognitive decline and dementia but there is a large variation in the quality, design of and results reported from these investigations. We have undertaken a systematic review of the evidence for the association between vitamin B₁₂ status and cognitive decline in older adults. A database search of the literature to 2011 was undertaken, using keywords related to vitamin B₁₂ and cognition. All prospective cohort studies assessing the association of serum vitamin B₁₂ or biomarkers were included. Quality assessment and extraction of the data were undertaken by two researchers. The quality assessment tool assigns a positive, neutral or negative rating. Of 3772 published articles, thirty-five cohort studies (n 14 325 subjects) were identified and evaluated. No association between serum vitamin B₁₂ concentrations and cognitive decline or dementia was found. However, four studies that used newer biomarkers of vitamin B₁₂ status (methylmalonic acid and holotranscobalamin (holoTC)) showed associations between poor vitamin B₁₂ status and the increased risk of cognitive decline or dementia diagnosis. In general, the studies were of reasonable quality (twenty-one positive, ten neutral and four negative quality) but of short duration and inadequate subject numbers to determine whether an effect exists. Future studies should be of adequate duration (at least 6 years), recruit subjects from the seventh decade, choose markers of vitamin B₁₂ status with adequate specificity such as holoTC and/or methylmalonic acid and employ standardised neurocognitive assessment tools and not screening tests in order to ascertain any relationship between vitamin B₁₂ status and cognitive decline.

Replacement of linoleic acid with α-linolenic acid does not alter blood lipids in normolipidaemic men

The effect of partial dietary replacement of linoleic acid (18:2n-6; linoleic acid-rich diet) with alpha-linolenic acid (18:3n-3; alpha-linolenic acid-rich diet) on plasma lipids was investigated in twenty-nine healthy young men. After a 2-week stabilization period subjects were randomly assigned to either the alpha-linolenic acid-rich diet group (n 15), receiving a mean of 10.1 g of alpha-linolenic acid and 12.1 g of linoleic acid/d, or the linoleic acid-rich diet group (n 14), receiving a mean of 1.0 g of alpha-linolenic acid and 21.0 g of linoleic acid/d, for a 6-week test period. Blood samples were taken at the commencement of the stabilization period and at the start (week 0), midpoint (week 3) and endpoint (week 6) of the test period and plasma lipids analysed. The changes occurring on the linoleic acid-rich diet and alpha-linolenic acid-rich diet were compared but no significant differences in the changes in plasma total cholesterol, LDL-cholesterol, HDL-cholesterol, the subfractions HDL2 and HDL3 or triacylglycerols were found. These results indicate that dietary replacement of linoleic acid with alpha-linolenic acid in the diet of healthy male subjects offers similar cardioprotective benefits with respect to lipid metabolism.