The effect of fiscal policy on diet, obesity and chronic disease : a systematic review

Objective To assess the effect of food taxes and subsidies on diet, body weight and health through a systematic review of the literature.

Methods We searched the English-language published and grey literature for empirical and modelling studies on the effects of monetary subsidies or taxes levied on specific food products on consumption habits, body weight and chronic conditions. Empirical studies were dealing with an actual tax, while modelling studies predicted outcomes based on a hypothetical tax or subsidy.

Findings Twenty-four studies met the inclusion criteria: 13 were from the peer-reviewed literature and 11 were published on line. There were 8 empirical and 16 modelling studies. Nine studies assessed the impact of taxes on food consumption only, 5 on consumption and body weight, 4 on consumption and disease and 6 on body weight only. In general, taxes and subsidies influenced consumption in the desired direction, with larger taxes being associated with more significant changes in consumption, body weight and disease incidence. However, studies that focused on a single target food or nutrient may have overestimated the impact of taxes by failing to take into account shifts in consumption to other foods. The quality of the evidence was generally low. Almost all studies were conducted in high-income countries.

Conclusion Food taxes and subsidies have the potential to contribute to healthy consumption patterns at the population level. However, current evidence is generally of low quality and the empirical evaluation of existing taxes is a research priority, along with research into the effectiveness and differential impact of food taxes in developing countries.

Technographic research in online education : context, culture and ICT consumption

Technologically-mediated learning environments are an increasingly common component of university experience. In this paper, the authors consider how the interrelated domains of policy contexts, new learning cultures and the consumption of information and communication technologies might be explored using the concept of technography. Understood here as a term referring to “the apprehension, reception, use, deployment, depiction and representation of technologies” (Woolgar, 2005, pp. 27-28), we consider how technographic studies in education might engage in productive dialogues with interdisciplinary research from the fields of cultural and cyber studies. We argue that what takes place in online learning and teaching environments is shaped by the logics and practices of technologies and their role in the production of new consumer cultures.

Why do some socioeconomically disadvantaged women eat better than others? An investigation of the personal, social and environmental correlates of fruit and vegetable consumption

The purpose of this paper was to examine the contribution of individual, social and environmental factors to predicting fruit and vegetable consumption among women of low socioeconomic position (SEP). An Australian community sample of 355 women of low SEP provided survey data on sociodemographic information, diet (fruit and vegetable consumption), and various cognitive, behavioural, social and perceived environmental influences on healthy eating. Information on the availability and accessibility of major chain supermarkets and fruit and vegetable stores from participant's residence was collected through objective audits. Women who were older, dieting to lose weight, had a greater taste preference for fruit and perceived the cost of fruit to be lower were more likely to be high fruit consumers. Women who had a high BMI were more likely to be high vegetable consumers. Women who perceived a greater availability of healthy foods in their neighbourhoods were more likely to be high fruit and vegetable consumers. Strategies aimed at increasing fruit and vegetable consumption among low SEP women should focus on modifying perceptions about the cost, availability and taste of fruits and vegetables. Tailoring nutrition interventions to accommodate differences in age, weight-control practices and weight status may also prove beneficial.

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.

A family-based intervention to increase fruit and vegetable consumption in adolescents : a pilot study

Objective: To evaluate the feasibility and effectiveness of a pilot family-based newsletter intervention to increase fruit and vegetable (FV) consumption among adolescents.
Design: Family-based, two-group randomised control trial with baseline, postintervention and follow-up measures. The intervention group received two FV newsletter packs over a 1 month period by postal mail. Social cognitive and behavioural choice theories provide the theoretical framework for the design and development of intervention materials. Control families were provided with all intervention materials at the end of the study. Adolescent FV consumption was assessed by an FFQ. Adolescent-reported barriers to eating FV, FV habits and preferences were the secondary outcomes, along with parent FV consumption, and parents reported knowledge, encouragement, home availability and accessibility of FV. Repeated-measures ANOVA was used to detect differences in behavioural and psychosocial outcomes between groups, time and group-by-time.
Setting: East Midlands, UK.
Subjects: Forty-nine parents and adolescents aged 12–14 years.
Results: Process evaluation indicated high reach, dose acceptability and fidelity of the intervention. At post-intervention and 6 weeks later at follow-up, adolescents in the intervention group had significantly higher fruit: (P0<·01) and vegetable (P<0·05) consumption and higher preferences for vegetables (P<0·01), compared with the control group. At post-intervention and follow-up, parents in the intervention group had significantly higher fruit (P<0·001) and vegetable (P<0·01) consumption and reported higher accessibility of fruit and vegetables (P<0·001), compared with those in the control group.
Conclusions: Family-based, newsletter interventions promoting FV consumption to adolescents appear to be feasible and effective at increasing FV consumption.

A cluster randomised trial of a telephone-based intervention for parents to increase fruit and vegetable consumption in their 3-to 5-year-old children : study protocol

Background: Inadequate fruit and vegetable consumption in childhood increases the risk of developing chronic disease. Despite this, a substantial proportion of children in developed nations, including Australia, do not consume sufficient quantities of fruits and vegetables. Parents are influential in the development of dietary habits of young children but often lack the necessary knowledge and skills to promote healthy eating in their children. The aim of this study is to assess the efficacy of a telephone-based intervention for parents to increase the fruit and vegetable consumption of their 3- to 5-year-old children.
Methods/Design: The study, conducted in the Hunter region of New South Wales, Australia, employs a cluster randomised controlled trial design. Two hundred parents from 15 randomly selected preschools will be randomised to receive the intervention, which consists of print resources and four weekly 30-minute telephone support calls delivered by trained telephone interviewers. The calls will assist parents to increase the availability and accessibility of fruit and vegetables in the home, create supportive family eating routines and role-model fruit and vegetable consumption. A further two hundred parents will be randomly allocated to the control group and will receive printed nutrition information only. The primary outcome of the trial will be the change in the child's consumption of fruit and vegetables as measured by the fruit and vegetable subscale of the Children's Dietary Questionnaire. Pre-intervention and post-intervention parent surveys will be administered over the telephone. Baseline surveys will occur one to two
weeks prior to intervention delivery, with follow-up data collection calls occurring two, six, 12 and 18 months following baseline data collection.
Discussion: If effective, this telephone-based intervention may represent a promising public health strategy to increase fruit and vegetable consumption in childhood and reduce the risk of subsequent chronic disease.
Trial registration: Australian Clinical Trials Registry ACTRN12609000820202

Consumer awareness and self-reported behaviours related to salt consumption in Australia

Australians are eating far more salt than is good for health. In May 2007, the Australian Division of World Action on Salt and Health (AWASH) launched a campaign to reduce population salt intake. A consumer survey was commissioned to quantify baseline aspects of awareness and behaviour related to salt and health amongst Australians. A total of 1084 individuals aged 14 years or over were surveyed by ACA Research using an established consumer panel. Participants were selected to include people of each sex, within different age bands, from major metropolitan and other areas of all Australian states and territories. Participants were invited via email to complete a brief questionnaire online. Two-thirds knew that salt was bad for health but only 14% knew the recommended maximum daily intake. Seventy percent correctly identified that most dietary salt comes from processed foods but only a quarter regularly checked food labels for salt content. Even fewer reported their food purchases were influenced by the salt level indicated (21%). The survey showed a moderate understanding of how salt effects health but there was little evidence of action to reduce salt intake. Consumer education will be one part of the effort necessary to reduce salt intake in Australia and will require government investment in a targeted campaign to achieve improvements in knowledge and behaviours.

'Traffic-light' nutrition labelling and 'junk-food' tax : a modelled comparison of cost-effectiveness for obesity prevention

Introduction: Cost-effectiveness analyses are important tools in efforts to prioritise interventions for obesity prevention.
Modelling facilitates evaluation of multiple scenarios with varying assumptions. This study compares the cost-effectiveness of
conservative scenarios for two commonly proposed policy-based interventions: front-of-pack ‘traffic-light’ nutrition labelling
(traffic-light labelling) and a tax on unhealthy foods (‘junk-food’ tax).
Methods: For traffic-light labelling, estimates of changes in energy intake were based on an assumed 10% shift in consumption
towards healthier options in four food categories (breakfast cereals, pastries, sausages and preprepared meals) in 10% of adults. For the ‘junk-food’ tax, price elasticities were used to estimate a change in energy intake in response to a 10% price increase in seven food categories (including soft drinks, confectionery and snack foods). Changes in population weight and body mass index by sex were then estimated based on these changes in population energy intake, along with subsequent impacts on disability-adjusted life years (DALYs). Associated resource use was measured and costed using pathway analysis, based on a health sector perspective (with some industry costs included). Costs and health outcomes were discounted at 3%. The cost-effectiveness of each intervention was modelled for the 2003 Australian adult population.
Results: Both interventions resulted in reduced mean weight (traffic-light labelling: 1.3 kg (95% uncertainty interval (UI): 1.2;
1.4); ‘junk-food’ tax: 1.6 kg (95% UI: 1.5; 1.7)); and DALYs averted (traffic-light labelling: 45 100 (95% UI: 37 700; 60 100);
‘junk-food’ tax: 559 000 (95% UI: 459 500; 676 000)). Cost outlays were AUD81 million (95% UI: 44.7; 108.0) for traffic-light
labelling and AUD18 million (95% UI: 14.4; 21.6) for ‘junk-food’ tax. Cost-effectiveness analysis showed both interventions were
‘dominant’ (effective and cost-saving).
Conclusion: Policy-based population-wide interventions such as traffic-light nutrition labelling and taxes on unhealthy foods are
likely to offer excellent ‘value for money’ as obesity prevention measures.

The influence of sodium on liking and consumption of salty food

Excessive sodium (Na) intake has been linked to development of hypertension and related pathologies. In this study, we assessed if the sodium chloride (NaCl) concentration in a prototypical food influences the liking and intake of that food. In study 1, detection and recognition thresholds for NaCl were assessed, and perceived salt intensity and liking for hash browns of varying sodium concentrations (40 mg, 120 mg, 170 mg, and 220 mg Na/100 g) were compared in a lab setting. In study 2, detection and recognition thresholds for NaCl were assessed in a lab setting, and lunches consisting of hash browns, basic salad, and beverages were consumed freely in a dining setting on 4 separate occasions. Intake and liking ratings for hash browns were recorded after the lunch. In both studies, detection and recognition thresholds for NaCl were not associated with perceived saltiness, liking, or intake of hash browns. Liking and perceived salt taste intensity of hash browns were correlated (r = 0.547 P < 0.01), and in study 1 the 220 mg sodium hash brown was most liked (P < 0.05). In study 2, there was no association between Na concentration and liking or consumption of hash browns. In summary, liking of hash browns were influenced by whether testing was in a lab or dining room environment. In a dining room environment, large decreases (>50%) of sodium content of food were achievable with only minor decrease in liking and no effect on consumption of the food.