The effects of policy actions to improve population dietary patterns and prevent diet-related non-communicable diseases: scoping review

Poor diet generates a bigger non-communicable disease (NCD) burden than tobacco, alcohol and physical inactivity combined. We reviewed the potential effectiveness of policy actions to improve healthy food consumption and thus prevent NCDs. This scoping review focused on systematic and non-systematic reviews and categorised data using a seven-part framework: price, promotion, provision, composition, labelling, supply chain, trade/investment and multi-component interventions. We screened 1805 candidate publications and included 58 systematic and non-systematic reviews. Multi-component and price interventions appeared consistently powerful in improving healthy eating. Reformulation to reduce industrial trans fat intake also seemed very effective. Evidence on food supply chain, trade and investment studies was limited and merits further research. Food labelling and restrictions on provision or marketing of unhealthy foods were generally less effective with uncertain sustainability. Increasingly strong evidence is highlighting potentially powerful policies to improve diet and thus prevent NCDs, notably multi-component interventions, taxes, subsidies, elimination and perhaps trade agreements. The implications for policy makers are becoming clearer.

outcome, dating from January 2004 onwards were included. A PICOS approach (participants, interventions, comparators, outcomes and study design) was used to assess the retrieved studies (Table 1). Only reviews in English were considered.
One researcher (LH) conducted the searches and removed duplicates. All remaining titles and abstracts were screened independently by two researchers (LH and MA), based on the inclusion/exclusion criteria (Table 1). All papers deemed potentially eligible were retrieved in full-text form and again screened independently by two researchers. Discrepancies on whether to include or exclude reviews were resolved by consensus or by seeking the opinion of a senior team member (SC).
Data extraction Both empirical studies (presenting primary data) and modelling studies (using secondary data to project health outcomes) were included. However, the results were analysed and discussed separately, recognising their different natures.
Data extraction was done by one researcher using pre-designed and pre-piloted forms ( Table 2 and Supplementary file 1). Extracted data was independently verified by another researcher to ensure accuracy and completeness. Owing to logistical and time constraints, it was not possible to contact study authors regarding any unclear, missing or additional data.

Data categorisation
Evidence from the reviews was categorised using a seven-part framework, which was developed and refined from the '4Ps' marketing framework: 4 price, place, promotion and product. In social marketing these 4Ps are key in planning and implementing strategies and this translates well to a policy context. In the social marketing mix, product stands for the desired behaviour and what people will gain when they perform the behaviour, whereas in the policy context this refers to the actual product (for example, foods). Price refers to the cost exchanged for the promised benefits and place refers to the location where the goods are distributed. Finally, promotion refers to a persuasive communication strategy to influence change and can involve multiple channels and target groups. After extensive piloting the following categories were used: • Food price-policies influencing prices through taxes, subsidies or economic incentives; • Food promotion-advertising/marketing; particularly on children; media campaigns and health education; • Food provision-in specific settings: schools, communities or workplaces; • Food composition-reformulation or elimination; • Food labelling-nutrition labelling, calorie labelling in stores/ restaurants; • Food supply chain, trade and investment-including legislation or regulation affecting production policies or supply-chain logistics; • Multi-component interventions (including at least two of the categories described above).

Data analysis
We used a narrative synthesis to summarise the evidence of policy interventions to promote healthy eating patterns. 55 First, the data identified and included in this review were extracted in tables and grouped based on their type of intervention. The different types of interventions included are discussed under data categorisation Table 1. Inclusion/exclusion criteria

Participants Include Exclude
Systematic and non-systematic reviews reporting a quantitative assessment of the effects (intended or unintended) of actions to improve healthy eating

All studies considered ineligible
Interventions Systematic and non-systematic reviews evaluating the effects of dietary actions that are: implemented by government policy; applied experimentally; or adopted in specific settings

Comparators
Systematic and non-systematic reviews were included in the review where actions to improve healthy diet and actions promoting NCD prevention were evaluated or compared Reviews were excluded if no comparisons of different actions to improve healthy diet or preventing NCDs were presented

Outcomes
The primary outcome of interest was dietary intake (consumption) Secondary outcomes included changes in clinical/physiological indicators related to NCDs and behaviours associated with a healthy diet Process evaluations reporting on implementation of interventions or policies without any quantitative outcome data; data only on costs, feasibility or acceptability without an assessment of primary effects (intake); studies on individuals as opposed to groups or whole populations; under nutrition; micro-nutrient deficiencies, micro-nutrient fortification; supplements

Study design
Systematic and non-systematic reviews that consisted of modelling studies, secondary analyses, randomised controlled trials, natural experiments, before vs after interventions and modelling studies were included. Furthermore, this review included studies for all age groups and all populations from high-, middle-and low-income countries Commentary/opinion articles; purely qualitative evaluations with no quantitative assessment; data/statistics from monitoring and surveillance that were not directly linked to a policy intervention; reviews/studies of under nutrition Abbreviation: NCD, non-communicable disease.
The effects of policy actions to improve population diet L Hyseni et al food had no effect on consumption. Another RCT stated that a subsidy of 50% on F/V would increase consumption by 25%. Subsidies modelling: four studies stated a subsidy of 10% on F/V increases consumption by~5%, with one study estimating a 1.5% increase in consumption in response to a 1.8% price decrease. Three modelling studies found that subsidies paired with taxes (range 10-20%) could reduce total calories by~1%. Tax on SSBs: 16 studies modelled the effect of a 5-30% SSB tax and showed a reduction in consumption (5-48%) demonstrating that consumption was proportional to the taxes applied. Substitution effects modelling: four studies modelled substitution between beverages in response to a 5-20% tax and suggested that consumers would reduce caloric intake of SSBs, by 10-48% in adults and by 5-8% in children and increase consumption of other beverages such as milk, low-calorie beverages, tea and coffee.
One study suggested that a focus on a single nutrient may increase intakes of other unhealthy nutrients. Fat tax modelling: four studies showed that relatively small taxes on fat (5-17.5%; $0.005 per g) can reduce fat and/or saturated fat consumption by 0-3%, reduce consumption of certain high-fat foods, and induce substitution with lower-fat options.
Sugar subsidy modelling (1): an implicit sugar subsidy would result in a price decrease of 36% and an increase in consumption (7.5%).
Sodium tax modelling (1): a sodium tax that increased the price of salty foods by 40% would reduce sodium consumption by 6%.
Taxes based on nutrient profiling (8): taxes on 'unhealthy'/ The effects of policy actions to improve population diet L Hyseni et al A tax on saturated fat would cause a small rise in salt intake as a result of cross-price elasticity effects and might overall result in more deaths than it averts. In addition, the saturated fat tax also results in a decrease in F/V consumption of~2-4% Shultz et al. 24 Systematic review USA Aim: to assess the effects of the 2009 food package revisions on healthy food and beverage availability, breastfeeding outcomes, and dietary intake of WIC programme participants 5 years later using only peerreviewed research Outcomes: fruit intake Significant changes were observed in dietary intake in another study, with increased fruit consumption by 0.33 servings per day among Hispanic mothers enrolled in WIC

(b) Food promotion
Marketing/ advertising to children Gregori et al. 25 Systematic review of RCTs UK and USA Aim: to perform a SR aimed at assessing the effect of TV advertising Outcomes: nutrition intake 4 RCTs: showed that total kcal intake was significantly higher and considerable more snacks were consumed after exposure to FA than after the NA. One RTC showed that the obese and overweight groups ate significantly more than the healthy weight group, both with FA and with NA

Boyland and Halford 26
Review UK Aim: to study the effect of TV advertising and branding on food preference and eating behaviour Outcomes: food intake Two cross-sectional experimental studies found that exposure to food advertising increased food and calorie intake in all children. The obese and overweight groups ate significantly more than the healthy weight group, both with FA; and with NA

Hingle and Kunkel 27
Review US focused Aim: to analyze the role of food marketing and to evaluate intervention efforts to reduce exposure to advertising messages for unhealthy food products Outcomes: food consumption and obesity The IOM report concluded that there is strong evidence that advertising influences the short-term food consumption of children aged 2-11 years; moderate evidence that it influences the regular diet of children aged 2-5 years; and weak evidence that it influences children aged 6-11 years.
Economics study (1): estimates that the impact of banning food advertisements on television would reduce the baseline rate of childhood obesity in the USA from 17% to somewhere in the range of 10.5-14.5% Nutrition education Mytton et al. 28 Systematic review and meta-analysis of RCTs Europe, North America and India Aim: to study the effects of either an increased or no increase in fruit and vegetable intake Outcomes: energy and fruit and vegetable intake RCTs (8): No significant differences (P = 0.93) were found in change in energy intake among studies supporting a general increase in F/V consumption (193 kJ) and studies providing a specific fruit portion per day (768 kJ).
Two RCTs found that the difference in F/V intake between the arms (dietary advice vs no advice) were 294 g and 5.7 portions, with a follow-up duration of 4 and 52 weeks, respectively Harris et al. 29 Systematic review of RCTs The effects of policy actions to improve population diet L Hyseni et al there was a reported increase of 23% in F/V intake of 5+ servings per day. In 2011, 60.4% of the population was reported to be consuming the recommended two serves of fruit daily and 66% of the population was consuming the recommended three serves of vegetables a day The effects of policy actions to improve population diet L Hyseni et al Review of policy documents 17 EU member states Aim: to identify and assess healthy eating policies at national level Outcomes: fruit and vegetable intake School (1): fruit consumption as a morning snack among children at MS increased (6.5% after vs 3.6% before). Fruit consumption in general also increased among adolescents (17% after vs 4% before), whereas SSB consumption decreased (3.3% after vs 9.6% before).
The effects of policy actions to improve population diet L Hyseni et al One double-blinded, randomised, cross-over, intervention study modified the fat content through feeding and found that the SFA content was reduced by 16.1% and the MUFA and PUFA content was increased by 9.9% and 7.5%, respectively. The reductions in LDL levels would be equivalent to a reduction in absolute risk of CHD and stroke of 7% and 5%, respectively.

A SR and meta-analysis of RCTs suggested that
The effects of policy actions to improve population diet L Hyseni et al Of key concern in the Pacific region has been the increasing import of fatty products and the, therefore, One study modelled extending the VAT at 17.5% in the UK and Northern Ireland to food products that were the main sources of saturated fat. They calculated that saturated fat consumption would reduce deaths from ischaemic heart disease by 1.8-2.6%, or 1800-2500 deaths per year in the country The effects of policy actions to improve population diet L Hyseni et al The effects of policy actions to improve population diet L Hyseni et al and are adapted from the 4P's marketing framework. Most interventions have subcategories, for example, food provision, which can be done in schools, communities or at workplaces. Within these categories the data were grouped according to the subcategories. Furthermore, as this review is about healthy eating, multiple nutrients are included. So another layer was added for these nutrients and the results were presented under their specific (sub-) categories for each of the nutrients. This structure was then used to present the results. All the evidence for each sub-category was reviewed and analysed according to study design and the number of studies included investigating the same intervention and outcome. The key findings are presented in the results section and all the studies are then summarised in the tables.
As the study designs and evidence per nutrition varies greatly no quantitative comparison will be made between the interventions. They will each be presented separately.

RESULTS
About 1805 candidate publications were screened and 197 papers were retrieved for full-text screening. In all 139 were excluded as they had no quantitative outcomes or outcomes different to our inclusion criteria. We identified 58 systematic and non-SRs for inclusion ( Figure 1). Eight reviews provided information on more than one category.
However, taxing unhealthy food may cause substitution effects. For instance, a fat tax might reduce saturated fat content but increase salt content and product consumption. 23 Four modelling studies included in Thow et al. 22 investigated these substitution effects. A 5-20% SSB tax could reduce calorie intake of SSBs by 10-48% in adults and by 5-8% in children, however consumption of milk, tea, coffee and low-calorie beverages may increase correspondingly. 22 Finally, Welsh et al. 7 included a modelling study suggesting that a US penny-per-ounce tax might reduce SSB consumption by 15% among adults and subsequently prevent 95 000 coronary heart events,~8000 strokes and~26 000 premature deaths.
Several reviews included at least one modelling study investigating a 'fat tax'. 9,10,19,22 All suggested that changes in fat The effects of policy actions to improve population diet L Hyseni et al consumption would be minor, unless the tax was substantial. Four modelling studies in Thow et al. 22 suggested that a small fat tax (5-17%) might reduce (saturated) fat consumption by 0-3% and induced substitution with lower-fat options. Increasing the price of salty foods by 40% was suggested to reduce sodium consumption by~6%. 22 Mozaffarian et al. 20 included a modelling study investigating a combination of taxing less healthy foods and using the $580 million revenue raised to subsidise fruit and vegetables. This might alter consumption to prevent~6000 CVD and cancer deaths annually.
Subsidies. Powell et al. included six modelling studies reporting − 0.49 mean price elasticity for fruit and vegetables, suggesting a 20% subsidy on fruit and vegetables might increase consumption by 10%, 18 while a 10% subsidy might increase consumption by 5%. 22 A continuing price reduction on fruit and vegetables might prevent~6700 cases of CHD and 2950 cases of ischaemic stroke. 21 Food promotion Marketing and advertising. Four randomised controlled trials (RCTs) in Gregori et al. 25 (Table 2b) indicated that exposure to food advertisements compared with non-food advertisements increased calorie intake and snacks consumed. The effect appeared largest in obese children. Two cross-sectional studies by Boyland and Halford 26 supported these findings. Conversely, banning food advertisements on television might reduce the US baseline rate of childhood obesity by 2.5-6.5%. 27 Nutrition education. RCTs reviewed in two SRs suggested that nutrition education focused on fruit and vegetables could increase their intake by 0.4-1.4 servings per day. 28,30 Two additional RCTs reported a net increase of 0.4 servings per day. 6 A meta-analysis of RCTs found that e-learning interventions focused on dietary intake increased fruit and vegetable intake by 0.24 servings per day; reduced total fat (−0.8 g), saturated fat (−0.2 g) and daily energy intake (4 kcal). 29 Media campaigns. Three reviews focused on fruit and vegetables. [31][32][33] Benefits were modest at best.
Food provision in schools, communities or workplaces Schools. A cross-sectional and longitudinal study included in Levy et al. 6 (Table 2c) investigated the effect of eliminating access to SSBs on consumption and found reductions of 0.16 servings per day and 4%, respectively. Another time-series study found a 35% decline in consumption in schools after SSBs were removed from cafeteria vending machines. However, pupils obtained SSBs from home or non-cafeteria vending machines instead. 6 A modelling study by Patel and Cabana 36 suggested replacing SSBs with water might reduce intake by 235 kcal per day among 2-19 year olds.
Jaime and Lock 38 reviewed the effect of a free piece of fruit in schools in three RCTs. Fruit and vegetable intake increased by 0.30-0.44 servings per day. However, benefits were not necessarily sustained long term. 38 Fat intake was targeted by one RCT and two non-randomised studies in the same review, reporting decreases in saturated fat (0.9-5.2% of energy intake) and total fat (2.0-10.9%). 38 A meta-analysis of school interventions targeting fruit and vegetable intake found a higher effect when fruit juice was included (0.32 portions) compared with no fruit juice included (0.25 portions). 37 Communities. No reviews were found for community interventions and the effect on dietary intake or health outcomes.
Workplaces. Thompson and Ravia 30 reviewed RCTs of workbased interventions and reported 0.8 servings per day increase in fruit and vegetable intake. A meta-analysis of 36 RCTs also found a significant increase in daily fruit and vegetable consumption. 35 Five RCTs in Mhurchu et al. 34 focused on total fat intake as a percentage of energy and found reductions in both the intervention (−2.2 to − 9.1%) and control groups (+1.3 to − 1.8%).
Food composition Trans fats. Downs et al. 42 included two pre-post-test studies evaluating (Table 2d) the effectiveness of interventions aimed to reduce trans fatty acids (TFAs) in food. In Denmark average iTFA intake decreased from 4.5 g per day in 1976 to 1.5 g per day in 1995 and reduced to virtually zero after the ban in 2005. 34 In The Netherlands, voluntary reformulation of TFAs decreased daily energy intake from 1.0 to 0.8% (a 20% reduction). 42 Mozaffarian and Clarke 43 conducted two meta-analyses with 13 RCTs and 4 prospective studies to calculate the effect of reduced TFAs in partially hydrogenated vegetable oils by means of reformulation. The predicted risk reductions were greatest when replacing at least half of the iTFA in partially hydrogenated vegetable oils, with soybean oil or canola oil. 43 Food labelling Menu labelling. Two SRs evaluated the effect of menu labelling on dietary intake (Table 2e). Swartz et al. 46 included two non-blind RCTs that reported no significant impact of menu labelling on calorie consumption. However, when combining the labels and labels/information categories vs no label, the labelled condition consumed 180 fewer calories. 46 Similar results were found by a meta-analysis of 17 studies conducted by Sinclair et al. 45 Nutrition labelling. Observational studies in Campos et al. 47 reported an association between nutrition label use and fat consumption. Furthermore, experimental research included showed that participants tended to consume more energy reduced foods in terms of weight, but the overall energy intake was significantly lower. 47 The theoretical concern that labelling might lead to overconsumption of foods perceived as 'less unhealthy' and appeared to be unfounded in a cross-sectional study by Hawley et al. 49 Food supply chain, trade and investment Trade and market liberalisation. Evidence for the effect of trade (Table 2f) market liberalisation on dietary intake is contested. Traill suggested only 'modest' effects, 52 whereas a study included in Friel et al. 51 argues that liberalisation of Foreign Direct Investment through trade agreements with the USA significantly increased soft drink consumption within low-and middle-income countries.
Monetary subsidies and taxes. Thow et al. 21 included two modelling studies; one suggested that increasing value-added tax in the UK on the main sources of saturated fat might reduce consumption and thereby decrease CHD deaths by 1.8-2.6%. The other suggested that halving value-added tax on fruit and vegetables could decrease consumption of sugar (−6.5%), fat (−2.5%) and saturated fat (−3.6%). 21 Reformulation. Livingstone et al. 44 reviewed reformulation in the supply chain by altering the diet of cows and investigated the effect on milk and dairy products. A double-blinded randomised cross-over intervention study found a 16% decrease in saturated fats and increase in monounsaturated fats (+10%) and polyunsaturated fats (+7.5%). A meta-analysis of RCTs suggested that replacing 10% of dietary saturated fat intake with polyunsaturated fats might reduce CHD risk by 10%. 44 Multi-component interventions Trans fats. Voluntary limits combined with mandatory labelling (Table 2g) were associated with a 30% reduction in dietary trans fat intake in the general population, in an interrupted time-series study in Downs et al. 42 Fruit and vegetables. Fifteen intervention studies in Blanchette and Burg 54 combined provision and promotion activities, and found an increase in fruit and vegetable intake of 2.54 servings per day. Conversely, single interventions rarely increased intake by more than 0.5 servings. [38][39][40] Salt. No reviews have evaluated the effects of multi-component interventions on salt intake. However, the UK salt programme has been evaluated and a 1.5 g per day (15%) reduction was observed between 2001 and 2011. This was achieved by sustained and progressive industry reformulation involving close monitoring and political pressure to ensure compliance, reinforced by media campaigns and traffic light food labelling. 56,57

Main findings
Our rapid scoping review suggests that 'upstream' interventions such as price interventions appear to be consistently effective in improving healthy eating. 9,16,[18][19][20][21]25 Multi-component interventions and reformulation also appear effective in promoting healthy diets. However, the effectiveness of the remaining policy interventions (labelling, restrictions on the provision or marketing of unhealthy food) generally demonstrated smaller effects and less certain long-term benefits. 29,36 Specific findings Food price. Taxes and subsidies appear to be consistently effective at reducing consumption of sugary drinks, 16,22 and increasing the consumption of fruit and vegetables. 18,21,22 Changes in consumption demonstrated price elasticity, thus the larger the taxes or subsidies, the greater the effect. 16,22 A fat tax, however, appeared to have smaller impacts on consumption, 9,19,22 and potential substitution effects need to be anticipated and negated. 22,23 Food promotion. Junk food advertisements significantly increase total calorie intake. Banning advertising to children therefore appears to offer an effective intervention to decrease intake and potentially reduce obesity levels. 25,26 Health promotion campaigns [31][32][33] and nutrition education 6,28-30 showed small effect sizes and benefits may diminish over time. More studies are needed to determine long-term effects.
Food provision. Most school-based interventions focused on fruit and vegetables 37,38 or access to SSBs. 6,36 Overall, these interventions seemed to be effective in the short term but effect sizes are generally small and longer-term effects were not routinely investigated.
The majority of workplace interventions focused on fruit and vegetable intake, 30,35 with a few focusing on fat intake, 34 and effects were generally modest.
Food composition. Mandatory reformulation to eliminate trans fat was very effective in Denmark, reducing consumption far more than voluntary reformulation. This is in line with a modelling study comparing voluntary with mandatory salt reformulation policies. 58 Furthermore, Cappuccio et al. 59 suggested that nation-wide reformulation policies might reduce salt consumption by 1 g per day.
Food labelling. Although menu labelling appears weak or ineffective, food labelling may help consumers to choose and purchase healthier options, 46 while also exerting pressure on manufacturers to reformulate. 60 Furthermore, although 50% of EU consumers might use food labels; many report difficulties in interpreting the labels. 47,61 However, the current evidence is based on diverse methodologies and remains limited. 62 Food supply chain, trade and investment. Food supply chain interventions appear intuitively powerful, but are underresearched. Interventions could take place at many levels of the food supply chain, with positive (or negative) effects on food availability, price, quality or marketing. [51][52][53] Targeted reformulation, subsidies and taxes in the food supply chain could have beneficial effects on diet-related health outcomes. 44 Multi-component interventions. Multi-component interventions appear to be highly effective at reducing the dietary intake of salt, industrial trans fats and increasing fruit and vegetable consumption, thus improving health outcomes at population level. 56,57 However, salt intake remains very high in most countries; often double the World Health Organisation recommended maximum levels of 5 g per day. 63 Likewise, industrial trans fat levels have been slashed in Denmark, the USA and parts of Western Europe but remain high elsewhere. 42 Furthermore, the reviews included only considered trans fat and fruit and vegetable intake. It is, therefore, not clear whether multi-component interventions might be equally effective for other dietary components such as sugar and total fat.

Strengths of this analysis
This scoping review used two independent researchers to screen all the papers generated through the searches. Discrepancies were resolved through consensus or consulting a third senior researcher. Furthermore, a systematic approach was used based on the seven-item interventions framework.
Food supply chain, trade and investment is an underexplored area; however there is some evidence to suggest that globalisation and liberalisation of markets can influence dietary patterns and NCDs. Multi-component interventions are as suggested effective to reduce dietary intake and NCDs. Countries have implemented several policies at the same time and it is important to quantify the impact compared with single policies.

Limitations of this analysis
This scoping review has several limitations. First, we only searched for reviews from the last 10 years. However, we anticipate this captured majority of relevant reviews and thus provide an excellent overview of current food policy interventions. Second, only reviews with an abstract available in English were included. Third, this scoping review focussed on systematic and non-SRs only, thereby missing areas lacking such reviews. However, we explicitly included both systematic and non-SRs to explore underresearched areas. Fourth, some effect measures were too unclear to include in the tables because it was not possible to go back to individual studies. Furthermore, as our inclusion criteria were only focused on dietary intake (consumption) and health outcomes; studies considering any other precursors to dietary behaviour such as purchasing behaviour, awareness, knowledge, preferences and availability were not presented. Also, most studies included were conducted in high-income or middle-income countries; generalisation of the results to low-income settings might be problematic. Fifth, whereas the effects of price interventions can be quantified and occurred immediately, nutrition education and health promotion campaigns have long-term effects that cannot be so easily measured. Finally, systematic and non-SRs included many different study methodologies. Outputs from RCTs, observational cohorts, natural experiments and modelling studies are all potentially valid, but may not be directly comparable and should therefore be interpreted with caution. We have, therefore, routinely presented such results separately.

Future research
The logical next step is to conduct a fully resourced SR that includes all relevant primary studies. This could explore whether effectiveness varies in different ethnic or socioeconomic subgroups, as socioeconomic deprivation is often associated with increased intake of foods high in saturated fat and sugar, poor nutrition and poorer health. Downstream interventions (such as advice to individuals) may widen the inequalities gap, whereas population-based policy interventions may reduce inequalities. Finally, the few analyses of multi-component interventions suggest that they may be more effective than single interventions. Further research is needed in all these areas.

CONCLUSIONS
Diverse policy interventions exist to improve healthy eating and thus prevent NCD. The evidence base varies for each category and nutrient. The evidence base for price interventions appears to be comprehensive and included studies mostly on taxing SSBs, followed by taxing dietary fat. Studies investigating the effect of subsidies mainly focused on fruit and vegetable intake. Taxes consistently decrease SSB consumption, whereas subsidies increase fruit and vegetable intake. Only a few reviews were included for food composition. The Denmark trans fat story suggests that voluntary reformulation can be effective to start with; however, a legislative ban is able to then essentially eliminate industrial trans fat consumption. Mandatory reformulation is thus consistently more effective than voluntary reformulation. Health promotion campaigns and nutrition education benefits appear modest and effects usually reduce over time.
Limiting the marketing of junk food and sugary drinks appears to be effective and, thus, a ripe target for regulation.
Workplace interventions appeared to be modestly effective at increasing fruit and vegetable intake. School interventions showed a modest effect of reducing SSB consumption and increase fruit and vegetable consumption in schools. The effects for food labelling were mixed. Labelling may help pressure reformulation by manufacturers and inform consumer choice. However, much depends on individual awareness, knowledge and ability to interpret labels correctly. Trade and investment factors controlling the food supply chain may be powerful but are currently underresearched. Finally, multi-component interventions appear to be more effective than single interventions. This might be predicted, having previously been reported in tobacco control, where comprehensive, coordinated programs are superior to single interventions. 64