Socioeconomic inequalities in diet and bodyweight: Evidence, causes, and intervention options

Diets low in fruits, vegetables, and whole grains, and high in saturated fat, salt, and sugar are the major contributors to the burden of chronic diseases globally. Previous research, and studies in this issue of Public Health Nutrition (PHN), show that unhealthy diets are more commonly observed among socioeconomically disadvantaged groups, and are key contributors to their higher rates of chronic disease. Most research examining socioeconomic inequalities in diet and bodyweight has been descriptive, and has focused on identifying the nature, extent, and direction of the inequalities. These types of studies are clearly necessary and important. We need however to move beyond description of the problem and focus much more on the question of why inequalities in diet and bodyweight exist. Furthering our understanding of this question will provide the necessary evidence-base to develop effective interventions to reduce the inequalities. The challenge of tackling dietary inequalities however doesn’t finish here: a maximally effective approach will also require equity-based policies that address the unequal population-distribution of social and economic resources, which is the fundamental root-cause of dietary and bodyweight inequalities.

Comparing multilevel and Bayesian spatial random effects survival models to assess geographical inequalities in colorectal cancer survival: a case study

Background Multilevel and spatial models are being increasingly used to obtain substantive information on area-level inequalities in cancer survival. Multilevel models assume independent geographical areas, whereas spatial models explicitly incorporate geographical correlation, often via a conditional autoregressive prior. However the relative merits of these methods for large population-based studies have not been explored. Using a case-study approach, we report on the implications of using multilevel and spatial survival models to study geographical inequalities in all-cause survival. Methods Multilevel discrete-time and Bayesian spatial survival models were used to study geographical inequalities in all-cause survival for a population-based colorectal cancer cohort of 22,727 cases aged 20–84 years diagnosed during 1997–2007 from Queensland, Australia. Results Both approaches were viable on this large dataset, and produced similar estimates of the fixed effects. After adding area-level covariates, the between-area variability in survival using multilevel discrete-time models was no longer significant. Spatial inequalities in survival were also markedly reduced after adjusting for aggregated area-level covariates. Only the multilevel approach however, provided an estimation of the contribution of geographical variation to the total variation in survival between individual patients. Conclusions With little difference observed between the two approaches in the estimation of fixed effects, multilevel models should be favored if there is a clear hierarchical data structure and measuring the independent impact of individual- and area-level effects on survival differences is of primary interest. Bayesian spatial analyses may be preferred if spatial correlation between areas is important and if the priority is to assess small-area variations in survival and map spatial patterns. Both approaches can be readily fitted to geographically enabled survival data from international settings

A framework for evaluating the impact of obesity prevention strategies on socioeconomic inequalities in weight

We developed a theoretical framework to organize obesity prevention interventions by their likely impact on the socioeconomic gradient of weight. The degree to which an intervention involves individual agency versus structural change influences socioeconomic inequalities in weight. Agentic interventions, such as standalone social marketing, increase socioeconomic inequalities. Structural interventions, such as food procurement policies and restrictions on unhealthy foods in schools, show equal or greater benefit for lower socioeconomic groups. Many obesity prevention interventions belong to the agento–structural types of interventions, and account for the environment in which health behaviors occur, but they require a level of individual agency for behavioral change, including workplace design to encourage exercise and fiscal regulation of unhealthy foods or beverages. Obesity prevention interventions differ in their effectiveness across socioeconomic groups. Limiting further increases in socioeconomic inequalities in obesity requires implementation of structural interventions. Further empirical evaluation, especially of agento–structural type interventions, remains crucial.

Assessing environmental inequalities in ambient air pollution across urban Australia

Identifying inequalities in air pollution levels across population groups can help address environmental justice concerns. We were interested in assessing these inequalities across major urban areas in Australia. We used a land-use regression model to predict ambient nitrogen dioxide (NO2) levels and sought the best socio-economic and population predictor variables. We used a generalised least squares model that accounted for spatial correlation in NO2 levels to examine the associations between the variables. We found that the best model included the index of economic resources (IER) score as a non-linear variable and the percentage of non-Indigenous persons as a linear variable. NO2 levels decreased with increasing IER scores (higher scores indicate less disadvantage) in almost all major urban areas, and NO2 also decreased slightly as the percentage of non-Indigenous persons increased. However, the magnitude of differences in NO2 levels was small and may not translate into substantive differences in health.

Evolution in design of integral leg prosthesis leads to improved outcomes

Developments of surgical attachments for bone-anchored prostheses are slowly but surely winning over the initial disbelief in the orthopedic community. Clearly, this option is becoming accessible to a wide range of individuals with limb loss. Seminal studies have demonstrated that the pioneering procedure relying on screw-type fixation engenders major clinical benefits and acceptable safety. The surgical procedure for press-fit implants, such as the Integral-Leg-Prosthesis (ILP) has been described Dr Aschoff and his team. Some clinical benefits of press-fit implants have been also established. Here, his team is once again taking a leading role by sharing the progression over 15 years of the rate of deep infections for 69 individuals with transfemoral amputation fitted with three successive refined versions of the ILP. By definition, a double-blind randomized clinical trial to test the effect of different fixation’s design is difficult. Alternatively, Juhnke and colleagues are reporting the outcomes of action-research study for a cohort of participants. The first and foremost important outcome of this study is the confirmation that the current design of the IPL and rehabilitation program are altogether leading to an acceptable rate of deep infection and other adverse events (e.g., structural failure of implant, periprosthetic factures). This study is also providing a strong insight onto the effect of major phases in redesign of an implant on the risk of infection. This is an important reminder that the development of a successful osseointegrated implant is unlikely to be immediate but the results of a learning curve made of empirical and sequential changes led by a reflective clinical practice. Clearly, this study provided better understanding of the safety of the ILP surgical and rehabilitation procedure while establishing standards and benchmark data for future studies focusing on design and infection of press-fit implants. Complementary observations of relationship between infection and cofounders such as loading of the prosthesis and prosthetic components used would be beneficial.Further definitive evidences of the clinical benefits with the latest design would be valuable, although an increase in health related quality of life and functional outcomes are likely to be confirmed. Altogether, the authors are providing compelling evidence that bone-anchored attachments particularly those relying on press-fit implants are an established alternative to socket prostheses.

The role of added sugar in a healthy diet and implications for health inequalities

The role of added sugar in a healthy diet and implications for health inequalities Sugars provide a readily available, inexpensive source of energy, can increase palatability and help preserve some foods. However added sugars also dilute the nutrient density of the diet. Further, consumption of sugar-sweetened beverages is associated with increased risk of weight gain and reduced bone strength, and high or frequent consumption of added sugars is associated with increased risk of dental caries, particularly in infants and young children. The products of the 2013 NHMRC Dietary Guidelines work program at www.eatforhealth.gov.au include the comprehensive evidence base about food, diet and health relationships and the dietary modeling used to inform recommendations. This presentation will detail the scientific evidence underpinning the revised dietary recommendations on consumption of foods and drinks containing added sugar and compare recommendations with the most recently available relevant Australian dietary intake and trend data. Differences in intakes of relevant food and drinks across quintiles of social disadvantage and in particular between Aboriginal and Torres Strait Islander groups and non-Indigenous Australians will also be explored.