Analysing health claims policy in Australia : a case study of evidence in food and nutrition policy-making

Purpose: Health claims generally describe an association between a food product and a health outcome. There is debate whether health claims promote or obstruct healthy food selection behaviour. This study investigates the role of evidence in food and nutrition policy-making. The research question is how and why was health claims policy made in Australia? The research is innovative in its critical analysis design and its focus on building theory to help improve food and nutrition policy-making processes and outcomes.

Methods: A case study design was adopted in which events, stakeholders and issues associated with the policy review were described from data generated from interviews and documentary sources. A content-analysis tool is being used to critically analyse textual data. Concepts in the text are being identified and relationships among the policy concepts, stakeholders and processes are being mapped.

Findings: The analysis of data associated with the policy review is revealing a pattern of relationships among stakeholders, processes and concepts around shared values, beliefs and interests towards food and health. Broader food regulation contexts have influenced the decision-making environment. The pattern of relationships shares common characteristics with Sabatier’s ‘Advocacy Coalition Framework’ theoretical explanation of policy-making.

Conclusions: The study findings have implications for health claims policy and practice in Australia. As a case study of evidence in food and nutrition policy-making, this research highlights the role of competing interests, beliefs and values in evidence interpretation. Challenges are identified in undertaking food policy research.

Oral sensitivity to fatty acids, food consumption and BMI in human subjects

Fatty acids are the chemical moieties that are thought to stimulate oral nutrient sensors, which detect the fat content of foods. In animals, oral hypersensitivity to fatty acids is associated with decreased fat intake and body weight. The aims of the present study were to investigate oral fatty acid sensitivity, food selection and BMI in human subjects. The study included two parts; study 1 established in thirty-one subjects (29 (sem 1·4) years, 22·8 (sem 0·5) kg/m²) taste thresholds using 3-AFC (3-Alternate Forced Choice Methodology) for oleic, linoleic and lauric acids, and quantified oral lipase activity. During study 2, fifty-four subjects (20 (sem 0·3) years, 21·5 (sem 0·4) kg/m2) were screened for oral fatty acid sensitivity using oleic acid (1·4 mm), and they were defined as hypo- or hypersensitive via triplicate triangle tests. Habitual energy and macronutrient intakes were quantified from 2 d diet records, and BMI was calculated from height and weight. Subjects also completed a fat ranking task using custard containing varying amounts (0, 2, 6 and 10 %) of fat. Study 1 reported median lipase activity as 2 μmol fatty acids/min per l, and detection thresholds for oleic, linoleic and lauric acids were 2·2 (sem 0·1), 1·5 (sem 0·1) and 2·6 (sem 0·3) mm. Study 2 identified twelve hypersensitive subjects, and hypersensitivity was associated with lower energy and fat intakes, lower BMI (P < 0·05) and an increased ability to rank custards based on fat content (P < 0·05). Sensitivity to oleic acid was correlated to performance in the fat ranking task (r 0·4, P < 0·05). These data suggest that oral fatty acid hypersensitivity is associated with lower energy and fat intakes and BMI, and it may serve as a factor that influences fat consumption in human subjects.

Dietitians' interests in primary food production: opportunities for greater involvement in the promotion of environmental sustainability

Dietitians are food communication professionals. Little is known about their views of food sustainability and security or of their interest in learning more about these issues. Therefore, an online survey of members of the Dietitians’ Association of Australia was conducted during the first half of 2012 about these issues.

Food sources of total energy and nutrients among U.S. infants and toddlers: national health and nutrition examination survey 2005-2012

Understanding the dietary intakes of infants and toddlers is important because early life nutrition influences future health outcomes. The aim of this study was to determine the dietary sources of total energy and 16 nutrients in a nationally representative sample of U.S. infants and toddlers aged 0-24 months. Data from the 2005-2012 National Health and Nutrition Examination Survey were analyzed. Dietary intake was assessed in 2740 subjects using one 24-h dietary recall. The population proportion was used to determine the contribution of foods and beverages to nutrient intakes. Overall infant formulas and baby foods were the leading sources of total energy and nutrients in infants aged 0-11.9 months. In toddlers, the diversity of food groups contributing to nutrient intakes was much greater. Important sources of total energy included milk, 100% juice and grain based mixed dishes. A number of foods of low nutritional quality also contributed to energy intakes including sweet bakery products, sugar-sweetened beverages and savory snacks. Overall non-flavored milks and ready-to-eat cereals were the most important contributors to micronutrient intakes. In conclusion this information can be used to guide parents regarding appropriate food selection as well as inform targeted dietary strategies within public health initiatives to improve the diets of infants and toddlers.

The relevance of the Heart Foundation of Australia's dietary recommendations for adult Australians : a comparison of views of general practitioners, cardiologists and dietitians

PURPOSE: To compare the views of general practitioners, cardiologists and dietitians about the relevance of the Heart Foundation of Australia's dietary recommendations for adult cardiac patients.

BASIC PROCEDURES: Quantitative-cross sectional study. Postal questionnaires were self-completed by 248 Victorian general practitioners (30% response), 189 Australia-wide cardiologists (47% response) and 180 Victorian dietitians (45% response). Responses were represented as percentages and analyses of variance were conducted to explore the impact of the independent variables: age, work status and gender on the dependent variable: dietary recommendation.

MAIN FINDINGS: Approximately half of the recommendations were viewed as strongly important to implement; these related to lean meats, limiting takeaways and cakes/biscuits, and adjusting energy intake. Others of importance were eating fruits, vegetables and fish. However, most of these goals were seen as difficult to achieve. Dietitians appeared to share responses of doctors, except for greater importance of eating fruit and vegetables and a greater difficulty in limiting cakes and biscuits. There was a high level of agreement among the three groups (mean 87%) about patients having difficulty implementing adjusting energy intake.

CONCLUSIONS: There is agreement amongst these professionals that many of the recommendations lack importance, specifically those pertaining to unsaturated oils, low fat dairy products, cholesterol rich foods, intake of legumes and grains and the restriction of salt. This may reflect a need for further nutrition education.

Vitamin B12 and cognitive impairment

Vitamin B12 is an essential vitamin required for neurological health. The main causes of deficiency (hypoacidity of the stomach, pernicious anemia, and lack of dietary intake) are more prevalent with increasing age. This chapter discusses the epidemiological evidence that suggests an association between low vitamin B12 levels and cognitive decline. To date, short term clinical trials have only shown B12 supplementation to be effective in improving cognition in those with preexisting deficiency (<150. ρmol/L). Improving dietary B12 intake by better food selection, fortified foods, or supplements, may have a role in maintaining cognitive function in those who are at risk of developing B12 deficiency. To be effective, such intervention may need to be commenced before the onset of neuronal damage in middle age, particularly in those with a B12 level of less than 250. ρmol/L. Trials to study when and for how long to provide B12 supplementation are needed.

Breeding habitat selection in an obligate beach bird: a test of the food resource hypothesis

The food resource hypothesis of breeding habitat selection in beach-nesting birds suggests that birds breed at sites with more prey to meet the increased energetic requirements associated with breeding. We compare prey resources using pitfall traps and core samples at breeding sites and absence sites of the eastern population of hooded plover, Thinornis rubricollis rubricollis, which, in this part of its range, is a threatened obligate beach bird. Breeding sites had higher abundances, equivalent species richness, and different assemblages of invertebrate prey compared with absence sites. Assemblages at breeding sites were characterised by more isopods, and fewer beetles of the family Phycosecidae. Breeding habitat selection by plovers appears to be associated with selection for sites with more food, and any process that degrades food resources at a site (e.g. kelp harvesting or marine pollution events) may reduce the likelihood of occupancy of that site by breeding birds.

Artificial selection for food colour preferences

Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection.

Reduced food access due to a lack of money, inability to lift and lack of access to a car for food shopping : a multilevel study in Melbourne, Victoria

Objective: To describe associations between demographic and individual and arealevel socio-economic variables and restricted household food access due to lack of money, inability to lift groceries and lack of access to a car to do food shopping.
Design: Multilevel study of three measures of restricted food access, i.e. running out of money to buy food, inability to lift groceries and lack of access to a car for food shopping. Multilevel logistic regression was conducted to examine the risk of each of these outcomes according to demographic and socio-economic variables.
Setting: Random selection of households from fifty small areas in Melbourne, Australia, in 2003.
Subjects: The main food shoppers in each household (n 2564).
Results: A lack of money was significantly more likely among the young and in households with single adults. Difficultly lifting was more likely among the elderly and those born overseas. The youngest and highest age groups both reported reduced car access, as did those born overseas and single-adult households. All three factors were most likely among those with a lower individual or household socio-economic position. Increased levels of area disadvantage were independently associated with difficultly lifting and reduced car access.
Conclusions: In Melbourne, households with lower individual socio-economic position and area disadvantage have restricted access to food because of a lack of money and/or having physical limitations due difficulty lifting or lack of access to a car for food shopping. Further research is required to explore the relationship between physical restrictions and food access.

Towards healthy and sustainable food consumption: an Australian case study

Objective To articulate a healthy and sustainable (H&S) diet; outline key health and environmental sustainability principles that can be applied in the selection of foods for inclusion in such a diet; and describe a methodology with which to assess the availability and affordability of a H&S food basket.

Design We synthesized publically available evidence on the environmental impact of different foods from academic, government, industry and non-government sources and constructed a hypothetical H&S equivalent of the typical Australian diet. Based on this, we constructed a weekly H&S food basket for a household of two adults and two children.

Setting Australia.

Subjects Australian populations.

Results The H&S diet is based on three overarching principles: (i) any food that is consumed above a person's energy requirement represents an avoidable environmental burden in the form of greenhouse gas emissions, use of natural resources and pressure on biodiversity; (ii) reducing the consumption of discretionary food choices, which are energy-dense and highly processed and packaged, reduces both the risk of dietary imbalances and the use of environmental resources; and (iii) a diet comprising less animal- and more plant-derived foods delivers both health and ecological benefits.

Conclusions We have focused on the articulation of a H&S diet not to facilitate ‘policy drift’ to focus on individual dietary choice, but rather to provide evidence to extend dietary guideline recommendations so as to integrate environmental considerations within the scope of food and health policy advice in Australia and elsewhere.

Conspecific attraction and nest site selection in a nomadic species, the zebra finch

Conspecific nesting density affects many aspects of breeding biology, as well as habitat selection decisions. However, the large variations in breeding density observed in many species are yet to be fully explained. Here, we investigated the settlement patterns in a colonial species with variable breeding density and where resource distribution could be manipulated. The zebra finch, Taeniopygia guttata, is a classic avian model in evolutionary biology but we know surprisingly very little about nest site selection strategies and nesting densities in this species, and in fact, in nomadic species in general. Yet, important determinants of habitat selection strategies, including temporal predictability and breeding synchrony, are likely to be different in nomadic species than in the non-nomadic species studied to date. Here, we manipulated the distribution of nesting sites (by providing nest boxes) and food patches (feeders) to test four non-exclusive habitat selection hypotheses that could lead to nest aggregation: 1) attraction to resources, 2) attraction to breeding conspecifics, and 3) attraction to successful conspecifics and 4) use of private information (i.e. own reproductive success on a site). We found that wild zebra finches used conspecific presence and possibly reproductive success, to make decisions over where to locate their nests, but did not aggregate around water or food within the study areas. Moreover, there was a high degree of inter-individual variation in nesting density preference. We discuss the significance of our results for habitat selection strategy in nomadic species and with respect to the differential selection pressures that individuals breeding at different densities may experience.

Effect of changes to the school food environment on eating behaviours and/or body weight in children: a systematic review

Previous school obesity-prevention reviews have included multi-component interventions. Here, we aimed to review the evidence for the effect of isolated food environment interventions on both eating behaviours (including food purchasing) and/or body weight. Five electronic databases were searched (last updated 30 November 2013). Of the 1,002 unique papers identified, 55 reported on school food environment changes, based on a review of titles and abstracts. Thirty-seven further papers were excluded, for not meeting the inclusion criteria. The final selection consisted of 18 papers (14 United States, 4 United Kingdom). Two studies had a body mass index (BMI) outcome, 14 assessed purchasing or eating behaviours and two studies assessed both weight and behaviour. Seventeen of 18 papers reported a positive outcome on either BMI (or change in BMI) or the healthfulness of food sold or consumed. Two studies were rated as strong quality and 11 as weak. Only three studies included a control group. A school environment supportive of healthy eating is essential to combat heavy marketing of unhealthy food. Modification of the school food environment (including high-level policy changes at state or national level) can have a positive impact on eating behaviours. A need exists, however, for further high-quality studies.

Habitat selection and energetics of the fiddler crab (Uca tangeri)

We tried to unravel the possible links between the skewed predation risk in Uca tangeri (where large individuals are more at risk from avian predators) and size-dependent changes in the physiology and habitat choice of this fiddler crab species. Over a transect running from low to high in the tidal zone of a beach in Mauritania, the temperature profile at various depths in the substrate, the water-table level of seep water, salt concentration of seep water, depth of the aerobic level, operative temperatures on the surface, and size distribution of crabs were assessed. In addition, resting metabolic rates, Q10 and thermal and starvation tolerances were estimated. Going from low to high in the tidal zone, crab size and burrow depth increased. At the preferred burrowing depth, microclimatological conditions appeared to be equally favourable at all sites. At the surface, conditions were more favourable low in the tidal zone, where also food availability is sufficient to enable small crabs to forage in the vicinity of their burrows. Large crabs have higher energy requirements and are thereby forced to forage in flocks low in the tidal zone where food is probably more abundant. Low in the tidal zone, digging deeply is impossible as the aerobic layer is rather thin. Large crabs prefer living high in the tidal zone as (1) deep burrows ensure better protection against predators, (2) more time is available for digging holes and (3) the substrate is better suited for reproduction. Energy reserves in late summer ensured an average of 34 days of survival. It is argued that the allotment of energy to growth must be considerable even in reproducing animals; the rewards of growth being the disproportional increase in reproductive output with size.

Fire affects microhabitat selection, movement patterns, and body condition of an Australian rodent (Rattus fuscipes)

Resource selection by animals influences individual fitness, the abundance of local populations, and the distribution of species. Further, the degree to which individuals select particular resources can be altered by numerous factors including competition, predation, and both natural- and human-induced environmental change. Understanding the influence of such factors on the way animals use resources can guide species conservation and management in changing environments. In this study, we investigated the effects of a prescribed fire on small-scale (microhabitat) resource selection, abundance, body condition, and movement pathways of a native Australian rodent, the bush rat (Rattus fuscipes). Using a before-after, control-impact design, we gathered data from 60 individuals fitted with spool and line tracking devices. In unburnt forest, selection of resources by bush rats was positively related to rushes, logs and complex habitat, and negatively related to ferns and litter. Fire caused selection for spreading grass, rushes, and complex habitat to increase relative to an unburnt control location. At the burnt location after the fire, rats selected patches of unburnt vegetation, and no rats were caught at a trapping site where most of the understory had been burnt. The fire also reduced bush rat abundance and body condition and caused movement pathways to become more convoluted. After the fire, some individuals moved through burnt areas but the majority of movements occurred within unburnt patches. The effects of fire on bush rat resource selection, movement, body condition, and abundance were likely driven by several linked factors including limited access to shelter and food due to the loss of understory vegetation and heightened levels of perceived predation risk. Our findings suggest the influence of prescribed fire on small mammals will depend on the resulting mosaic of burnt and unburnt patches and how well this corresponds to the resource requirements of particular species.