Evaluation of Economic and Health Outcomes Associated With Food Taxes and Subsidies: A Systematic Review and Meta-analysis

The relationship between the price and demand of alcohol, tobacco, unhealthy food, sugar-sweetened beverages, and gambling: an umbrella review of systematic reviews

BACKGROUND

The WHO highlight alcohol, tobacco, unhealthy food, and sugar-sweetened beverage (SSB) taxes as one of the most effective policies for preventing and reducing the burden of non-communicable diseases. This umbrella review aimed to identify and summarise evidence from systematic reviews that report the relationship between price and demand or price and disease/death for alcohol, tobacco, unhealthy food, and SSBs. Given the recent recognition as gambling as a public health problem, we also included gambling.

METHODS

The protocol for this umbrella review was pre-registered (PROSPERO CRD42023447429). Seven electronic databases were searched between 2000-2023. Eligible systematic reviews were those published in any country, including adults or children, and which quantitatively examined the relationship between alcohol, tobacco, gambling, unhealthy food, or SSB price/tax and demand (sales/consumption) or disease/death. Two researchers undertook screening, eligibility, data extraction, and risk of bias assessment using the ROBIS tool.

RESULTS

We identified 50 reviews from 5,185 records, of which 31 reported on unhealthy food or SSBs, nine reported on tobacco, nine on alcohol, and one on multiple outcomes (alcohol, tobacco, unhealthy food, and SSBs). We did not identify any reviews on gambling. Higher prices were consistently associated with lower demand, notwithstanding variation in the size of effect across commodities or populations. Reductions in demand were large enough to be considered meaningful for policy.

CONCLUSIONS

Increases in the price of alcohol, tobacco, unhealthy food, and SSBs are consistently associated with decreases in demand. Moreover, increasing taxes can be expected to increase tax revenue. There may be potential in joining up approaches to taxation across the harm-causing commodities.

The equitable impact of sugary drink taxation structures on sugary drink consumption among Canadians: a modelling study using the 2015 Canadian Community Health Survey-Nutrition

OBJECTIVE

Estimate the impact of 20 % flat-rate and tiered sugary drink tax structures on the consumption of sugary drinks, sugar-sweetened beverages and 100 % juice by age, sex and socio-economic position.

DESIGN

We modelled the impact of price changes - for each tax structure - on the demand for sugary drinks by applying own- and cross-price elasticities to self-report sugary drink consumption measured using single-day 24-h dietary recalls from the cross-sectional, nationally representative 2015 Canadian Community Health Survey-Nutrition. For both 20 % flat-rate and tiered sugary drink tax scenarios, we used linear regression to estimate differences in mean energy intake and proportion of energy intake from sugary drinks by age, sex, education, food security and income.

SETTING

Canada.

PARTICIPANTS

19 742 respondents aged 2 and over.

RESULTS

In the 20 % flat-rate scenario, we estimated mean energy intake and proportion of daily energy intake from sugary drinks on a given day would be reduced by 29 kcal/d (95 % UI: 18, 41) and 1·3 % (95 % UI: 0·8, 1·8), respectively. Similarly, in the tiered tax scenario, additional small, but meaningful reductions were estimated in mean energy intake (40 kcal/d, 95 % UI: 24, 55) and proportion of daily energy intake (1·8 %, 95 % UI: 1·1, 2·5). Both tax structures reduced, but did not eliminate, inequities in mean energy intake from sugary drinks despite larger consumption reductions in children/adolescents, males and individuals with lower education, food security and income.

CONCLUSIONS

Sugary drink taxation, including the additional benefit of taxing 100 % juice, could reduce overall and inequities in mean energy intake from sugary drinks in Canada.

Impact of price reductions, subsidies, or financial incentives on healthy food purchases and consumption: a systematic review and meta-analysis

Poor diets are a global concern and are linked with various adverse health outcomes. Healthier foods such as fruit and vegetables are often more expensive than unhealthy options. This study aimed to assess the effect of price reductions for healthy food (including fruit and vegetables) on diet. We performed a systematic review and meta-analysis on studies that looked at the effects of financial incentives on healthy food. Main outcomes were change in purchase and consumption of foods following a targeted price reduction. We searched electronic databases (MEDLINE, EconLit, Embase, Cinahl, Cochrane Library, and Web of Science), citations, and used reference screening to identify relevant studies from Jan 1, 2013, to Dec 20, 2021, without language restrictions. We stratified results by population targeted (low-income populations vs general population), the food group that the reduction was applied to (fruit and vegetables, or other healthier foods), and study design. Percentage price reduction was standardised to assess the effect in meta-analyses. Study quality was assessed using the Cochrane Risk of Bias tool and Newcastle-Ottawa Scale. 34 studies were eligible; 15 took place in supermarkets and eight took place in workplace canteens in high-income countries, and 21 were targeted at socioeconomically disadvantaged communities. Pooled analyses of 14 studies showed a price reduction of 20% resulted in increases in fruit and vegetable purchases by 16·62% (95% CI 12·32 to 20·91). Few studies had maintained the price reduction for over 6 months. In conclusion, price reductions can lead to increases in purchases of fruit and vegetables, potentially sufficient to generate health benefits, if sustained.

Fiscal policies and regulations for healthy diets in Sri Lanka: an analysis of the political economy of taxation and traffic light labelling for sugar-sweetened beverages

BACKGROUND

Unhealthy dietary patterns significantly contribute to rising non-communicable diseases (NCDs) in Sri Lanka. The government has implemented policy measures to promote healthy dietary patterns, including the traffic light labelling (TLL) system for sugar-sweetened beverages (SSBs) in 2016 and taxation on SSBs in 2017.

OBJECTIVES

To analyse how ideas, institutions, and power dynamics influence the formulation and implementation of these two interventions, and to identify strategies for public health actors to advocate for more effective food environment policies in Sri Lanka.

METHODS

This study drew on Kingdon's theory of agenda-setting and Campbell's institutionalist approach to develop the theoretical framework. We examined the political economy at the policy development and implementation stages, adopting a deductive framework approach for data collection and analysis. Data were collected from documents and key informants.

RESULTS

NCDs and nutrition are recognised and framed as important policy issues in health-sector policy documents, and the SSB tax and TLL system are seen as means of improving diets and health. Sri Lanka's commitment to addressing NCDs and nutrition-related issues is evident through these policies. The Ministry of Health led policy development, and key stakeholders were involved. However, there are opportunities to learn and strengthen policy in Sri Lanka and elsewhere. Limited involvement and commitment of some stakeholders in developing national policies, industry interferences, and other gaps resulted in weaker policy design. Gender considerations were also given minimal attention in policy formulation and implementation.

CONCLUSIONS

To enhance the effectiveness of the policies and regulations to promote healthy diets in Sri Lanka, comprehensive policy coverage, multistakeholder involvement and commitment to national policies, balanced power dynamics, technical feasibility, government commitment backed with high-level political support, awareness, and knowledge creation, managing industry interferences, integrating gender considerations are crucial factors.

Considerations for modelling a broad food tax in the Philippines and other low-income and middle-income countries

Fiscal policies to improve diet are a promising strategy to address the increasing burden of non-communicable disease, the leading cause of death globally. Sugar-sweetened beverage taxes are the most implemented type of fiscal policy to improve diet. Yet taxes on food, if appropriately structured and applied across the food supply, may support a larger population-level shift towards a healthier diet. Designing these policies and guiding them through the legislative process requires evidence. Equity-oriented cost-effectiveness analyses that estimate the distribution of potential health and economic gains can provide this critical evidence. Taxes on less healthy foods are rarely modelled in low-income and middle-income countries.We describe considerations for modelling the effect of a food tax, which can provide guidance for food tax policy design. This includes describing issues related to the availability, reliability and level of detail of national data on dietary habits, the nutrient content of foods and food prices; the structure of the nutrient profile model; type of tax; tax rate; pass-through rate and price elasticity. Using the Philippines as an example, we discuss considerations for using existing data to model the potential effect of a tax, while also taking into account the political and food policy context. In this way, we provide a modelling framework that can help guide policy-makers and advocates in designing a food policy to improve the health and well-being of future generations in the Philippines and elsewhere.

A sweet deal for domestic industry: the political economy and framing of Vanuatu's sugar-sweetened beverage tax

INTRODUCTION

The Government of Vanuatu introduced an excise tax on sugar-sweetened beverages (SSBs) in 2015. While lauded for its alignment with the WHO's Best Buys recommendations for addressing non-communicable diseases (NCDs), little is known about the tax's adoption process or whose interests it serves.

METHODS

Using case study methodology, this study examined how and why Vanuatu's SSB tax was introduced. Policy documents, key informant interviews (n=33) and direct observations were analysed using theories of policy analysis, power analysis and postcolonial theory to map the policy's adoption, surrounding political economy and the ideas, interests and institutions that shaped the tax and its framing.

RESULTS

The SSB tax emerged during a politically and economically unstable time in Vanuatu's history. The tax's links to the national health agenda were tenuous despite its ostensible framing as a way to combat NCDs. Rather, the tax was designed to respond to tightening economic and trade conditions. Spearheaded by several finance-focused bureaucrats, and with limited input from health personnel, the tax targeted less frequently consumed carbonated SSBs (which are mostly imported) without any revenue reinvestments into health. Driven by the desire to generate much-needed government revenue and instal domestic protections via selective implementation and carve-outs for local producers, the Vanuatu SSB tax did meet national objectives, just not the dual health and economic 'win-win' projected by the NCD Best Buys.

CONCLUSION

Vanuatu's SSB tax adoption process reveals the limitations of decontextualised policy recommendations, such as the NCD Best Buys, whose framing may be overcome by local political realities. This research highlights the need for further political economy considerations in global health recommendations, since contextual forces and power dynamics are key to shaping both how and why policies are enacted and also whose interest they serve.

Scaling up food pricing policies in the Pacific: a guide to action

There are calls for governments around the world to adopt pricing policies, including taxes, subsidies and price controls that ensure all people have access to, and can afford, healthy diets. Despite the strong potential of pricing policies to promote healthy diets and to support a post-COVID-19 recovery, there are gaps in evidence with regard to 'how' to design and apply effective food taxes in practice, and countries report challenges in navigating the different policy options.In this practice piece, we examine the global evidence for food taxes with a view to identifying practical lessons for policy design, adoption and implementation, using the Pacific Islands Region as a case study. We present a systematic resource that draws on locally generated evidence, and a Pacific conceptualisation of healthy diets, to address considerations in setting the tax base, rate and mechanisms, and to ensure tax targets are clearly identifiable within national tax and administrative systems. Health and Finance collaboration at the country level could ensure tax design addresses concerns for the impacts of food taxes on employment, economics and equity, as well as position food taxes as an opportunity to fund revenue shortfalls faced by governments following the COVID-19 pandemic. We demonstrate a need to review other policies for consistency with national health objectives to ensure that countries avoid inadvertently undermining health taxes, for example, by ensuring that foods with known non-communicable disease risk are not being price protected or promoted.

Bringing down barriers to children's healthy eating: a critical review of opportunities, within a complex food system

This narrative review revises the scientific evidence of recent years on healthy eating in children and adolescents, making sense of promising avenues of action, from a food system perspective. A conceptual framework is provided to better understand how eating habits of children and adolescents are shaped to identify key multisectoral approaches that should be implemented to promote healthier diets. The following influencing factors are discussed: individual factors (physiological and psychological factors, food preferences and food literacy competencies), factors within the personal and socio-cultural food environments, external food environments, and the supply chain. In each section, the main barriers to healthy eating are briefly discussed focussing on how to overcome them. Finally, a discussion with recommendations of actions is provided, anchored in scientific knowledge, and transferable to the general public, industry, and policymakers. We highlight that multidisciplinary approaches are not enough, a systems approach, with a truly holistic view, is needed. Apart from introducing systemic changes, a variety of interventions can be implemented at different levels to foster healthier diets in children through fostering healthier and more sustainable food environments, facilitating pleasurable sensory experiences, increasing their food literacy, and enhancing their agency by empowering them to make better food related decisions. Acknowledging children as unique individuals is required, through interpersonal interactions, as well as their role in their environments. Actions should aim to enable children and adolescents as active participants within sustainable food systems, to support healthier dietary behaviours that can be sustained throughout life, impacting health at a societal level.

Sugar-Sweetened Beverage Taxes and Perinatal Health: A Quasi-Experimental Study

INTRODUCTION

One in 5 pregnant individuals report consuming sugar-sweetened beverages at least once per day. Excess sugar consumption during pregnancy is associated with several perinatal complications. As sugar-sweetened beverage taxes become increasingly common public health measures to reduce sugar-sweetened beverage consumption, evidence of the downstream effects of sugar-sweetened beverage taxes on perinatal health remains limited.

METHODS

This longitudinal retrospective study examines whether sugar-sweetened beverage taxes in 5 U.S. cities were associated with decreased risk of perinatal complications, leveraging 2013-2019 U.S. national birth certificate data and a quasi-experimental difference-in-differences approach to estimate changes in perinatal outcomes. Analysis occurred from April 2021 through January 2023.

RESULTS

The sample included 5,324,548 pregnant individuals and their live singleton births in the U.S. from 2013 through 2019. Sugar-sweetened beverage taxes were associated with a 41.4% decreased risk of gestational diabetes mellitus (-2.2 percentage points; 95% CI= -4.2, -0.2), a -7.9% reduction in weight-gain-for-gestational-age z-score (-0.2 standard deviations; 95% CI= -0.3, -0.01), and decreased risk of infants born small for gestational age (-4.3 percentage points; 95% CI= -6.5, -2.1). There were heterogeneous effects across subgroups, particularly for weight-gain-for-gestational-age z-score.

CONCLUSIONS

Sugar-sweetened beverage taxes levied in five U.S. cities were associated with improvements in perinatal health. Sugar-sweetened beverage taxes may be an effective policy instrument for improving health during pregnancy, a critical window during which short-term dietary exposures can have lifelong consequences for the birthing person and child.

Comparison of Dietary Intake Before vs After Taxes on Sugar-Sweetened Beverages and Nonessential Energy-Dense Foods in Mexico, 2012 to 2018

Importance

Tax evaluations have shown effectiveness in reducing purchases of taxed items. However, few studies have looked at changes in overall dietary intake according to national surveys.

Objective

To estimate the contribution of taxed and untaxed beverages and foods to dietary intake over time, and the nutritional dietary profile in total beverages and foods consumed.

Design, Setting, and Participants

This cross-sectional study used data from 3 National Health and Nutrition Surveys of a nationally representative sample of participants aged older than 1 year in Mexico from 2012 (pretax), 2016, and 2018 (posttax). Data were analyzed from September 2021 to December 2022.

Exposure

Taxes on sugar-sweetened beverages and nonessential energy-dense foods implemented since 2014.

Main Outcomes and Measures

The outcomes were the contribution of taxed and untaxed beverages to total beverage volume, the contribution of taxed and untaxed foods to total food energy, and the energy density and content of added sugars and saturated fats. Outcomes were assessed with 24-hour recalls (24HR) (2012 and 2016) and Food Frequency Questionnaires (FFQ) (2012, 2016, and 2018), and were adjusted by sociodemographic and macroeconomic variables.

Results

A total of 17 239 participants were analyzed from 2012, 18 974 from 2016, and 30 027 from 2018; approximately 50% were men, and approximately 75% lived in urban areas. According to 24HRs, the contribution of taxed beverages to total beverage volume changed -2.3 (95% CI, -4.4 to -0.2) percentage points from 2012 to 2016, while water increased. The contribution of taxed foods to total food energy changed -3.0 (95% CI, -4.2 to -1.8) percentage points, while untaxed whole grains, processed meats, other animal sources, and sugars and desserts increased. The content in total beverages of added sugars changed -1.1 kcal/100 mL (95% CI, -2.0 to -0.2), and in total foods, the content of added sugar changed -0.6 %kcal (95% CI, -1.0 to -0.2), saturated fat changed -0.8 %kcal (95% CI, -1.1 to -0.4), and energy density changed -9.8 kcal/100 g (95% CI, -13.8 to -5.8). Main results were consistent with the FFQ (up to 2018), with some differences in subgroups and nutritional components.

Conclusions and Relevance

The findings of this study on 3 cross-sectional national dietary surveys are consistent with previous evaluations; after tax implementation, there was a decrease in the contribution of taxed items. Furthermore, some unhealthy untaxed items increased, but the content of unhealthful nutritional components, particularly added sugar, in overall beverages and foods decreased.

Effect of a relative pricing intervention and active merchandising on snack purchases: interrupted time series analysis of a hospital retailer-led strategy

BACKGROUND

Pricing policies have been shown to be an effective lever for promoting healthier dietary choices in consumer food environments. It is not yet well understood how pricing can be used to encourage healthier substitute purchases. The aim of the study was to assess the effect of a retailer-led relative pricing intervention on weekly purchases of targeted snack foods and beverages.

METHODS

This was an ecological analysis in a real-world large tertiary hospital consumer food environment setting in urban Canada, comprised of four retail outlets: two large cafeterias, one smaller cafeteria, and one grab-and-go café. An interrupted time series analysis was designed to evaluate the effect of Snacking Made Simple, a retailer-led relative pricing intervention applied to 10 popular snack foods and beverages (n = 87 weeks, 66 weeks baseline and 21 weeks intervention, April 2018 to December 2019), on weekly purchase differences between healthier and less healthy targeted items, adjusted for weekly sales volume. Five healthier items were price discounted, alongside a price increase for five less healthy items. The intervention was actively merchandised in keeping with behaviour change theory.

RESULTS

Weekly purchases of targeted snacks became healthier during the intervention period (β = 21.41, p = 0.0024). This followed a baseline period during which weekly purchases of less healthy targeted snacks had outpaced over time those of healthier targeted snacks (β = -11.02, p = 3.68E-14). We estimated that, all else being equal, a hypothetical 9.43 additional weeks of the intervention would be required to transition to net-healthier targeted snack purchases in this environment. The effects of the intervention varied by retail outlet, and the outcome appears driven by specific food items; further, examining merchandising implementation, we posited whether direct versus indirect substitution may have affected purchasing outcomes.

CONCLUSIONS

Relative pricing may be a promising way to incentivize healthier substitute purchasing in the consumer food environment. Added attention to merchandising strategy as well as value-add factors within food categories and their effects on price salience may be an important factor in effective intervention design.

An umbrella review of the effectiveness of fiscal and pricing policies on food and non-alcoholic beverages to improve health

Poor quality diets represent major risk factors for the global burden of disease. Modeling studies indicate a potential for diet-related fiscal and pricing policies (FPs) to improve health. There is real-world evidence (RWE) that such policies can change behavior; however, the evidence regarding health is less clear. We conducted an umbrella review of the effectiveness of FPs on food and non-alcoholic beverages in influencing health or intermediate outcomes like consumption. We considered FPs applied to an entire population within a jurisdiction and included four systematic reviews in our final sample. Quality appraisal, an examination of excluded reviews, and a literature review of recent primary studies assessed the robustness of our results. Taxes and, to some extent, subsidies are effective in changing consumption of taxed/subsidized items; however, substitution is likely to occur. There is a lack of RWE supporting the effectiveness of FPs in improving health but this does not mean that they are ineffective. FPs may be important for improving health but their design is critical. Poorly designed FPs may fail to improve health and could reduce support for such policies or be used to support their repeal. More high-quality RWE on the impact of FPs on health is needed.

Effect of Financial Incentives and Default Options on Food Choices of Adults With Low Income in Online Retail Settings: A Randomized Clinical Trial

Importance

Despite recent growth in online redemption of Supplemental Nutrition Assistance Program (SNAP) benefits, no previous work has tested the impact of economic and behavioral economic strategies on food purchasing behaviors in an online grocery retail setting among adults with low income.

Objective

To examine the extent to which financial incentives and default shopping cart options influence fruit and vegetable purchases.

Design, Setting, and Participants

This randomized clinical trial used an experimental online grocery store for adults who currently or have ever received SNAP benefits. From October 7 to December 2, 2021, participants were instructed to shop for a week's worth of groceries for their household, with a budget tailored to household size; no payment was taken.

Interventions

Random assignment to 1 of 4 conditions: no intervention, 50% discount on eligible fruits and vegetables, prefilled shopping carts with tailored fruit and vegetable items (ie, default options), or a combination of the discount and default options.

Main Outcomes and Measures

The primary outcome was the percentage of nondiscounted dollars spent on eligible fruit and vegetables per basket.

Results

Of 2744 participants, mean (SD) age was 46.7 (16.0) years, and 1447 (52.7%) identified as women. A total of 1842 participants (67.1%) reported currently receiving SNAP benefits and 1492 (54.4%) reported shopping online for groceries in the previous 12 months. Participants spent a mean (SD) 20.5% (23.5%) of total dollars on eligible fruits and vegetables. Compared with no intervention, those in the discount condition spent 4.7% (98.3% CI, 1.7%-7.7%) of more total dollars on eligible fruits and vegetables; those in the default condition, 7.8% (98.3% CI, 4.8%-10.7%) more; and those in the combination condition, 13.0% (98.3% CI, 10.0%-16.0%) more (P < .001 for all). There was no difference between the discount and the default conditions (P = .06), but the effect in the combination condition was significantly larger than both discount and default conditions (P < .001). Default shopping cart items were purchased by 679 participants (93.4%) in the default condition and 655 (95.5%) in the combination condition, whereas 297 (45.8%) in the control and 361 (52.9%) in the discount conditions purchased those items (P < .001). No variation was observed by age, sex, or race and ethnicity, and results were similar when those who reported never shopping online for groceries were excluded.

Conclusions and Relevance

In this randomized clinical trial, financial incentives for fruits and vegetables and default options, especially in combination, led to meaningful increases in online fruit and vegetable purchases among adults with low income.

Trial Registration

ClinicalTrials.gov Identifier: NCT04766034.

Fruit and vegetable consumption as a preventative strategy for non-communicable diseases

A high intake of fruit and vegetables (FV) has consistently been associated with a reduced risk of a number of non-communicable diseases. This evidence base is largely from prospective cohort studies, with meta-analyses demonstrating an association between increased FV intake and reduced risk of both CHD and stroke, although the evidence is less certain for cancer and diabetes. Controlled intervention trials examining either clinical or intermediate risk factor endpoints are more scarce. Therefore, evidence that FV consumption reduces the risk of disease is so far largely confined to observational epidemiology, which is hampered by some methodological uncertainties. Although increased FV intake is promoted across all dietary guidelines, national surveys confirm that dietary intakes are suboptimal and are not increasing over time. A range of barriers to increasing FV intake exist, including economic, physical and behavioural barriers that must be considered when exploring potential opportunities to change this, considering the feasibility of different approaches to encourage increased FV consumption. Such interventions must include consideration of context, for example, challenges and uncertainties which exist with the whole food system.

Impact of a farmers' market healthy food subsidy on the diet quality of adults with low incomes in British Columbia, Canada: a pragmatic randomized controlled trial

BACKGROUND

Adults with low incomes have lower diet quality than their higher income counterparts. In Canada, the British Columbia Farmers' Market Nutrition Coupon Program (FMNCP) provides coupons to low-income households to purchase healthy foods in farmers' markets.

OBJECTIVE

The objective of this study was to examine the impact of the FMNCP on the diet quality of adults with low incomes.

METHOD

In a pragmatic randomized controlled trial conducted in 2019, adults with low incomes (≥18 y) were randomly assigned either to an FMNCP intervention (n = 143) or a no-intervention control group (n = 142). The FMNCP group received 16 coupon sheets valued at $21 per sheet over 10-15 wk to purchase healthy foods from farmers' markets. Participants completed a questionnaire and 2 24-h dietary recalls at baseline (0 wk), immediately post-intervention (10-15 wk), and 16-wk post-intervention (26-31 wk). Diet quality was calculated using the Healthy Eating Index-2015 (HEI-2015). Linear mixed-effects regression assessed differences in HEI-2015 total (primary outcome) and component scores (secondary outcomes) between the FMNCP and control groups at post-intervention and 16-wk post-intervention. Subgroup analyses examined program impacts by sex and age group (18-59 y, ≥60 y).

RESULTS

There were no significant differences in HEI-2015 total scores between the FMNCP and control groups at post-intervention (-0.07; 95% CI: -4.07, 3.93) or 16-wk post-intervention (1.22; 95% CI: -3.00, 5.44) overall or between subgroups. There were no significant between-group differences in HEI-2015 component scores at post-intervention, although there were significant differences in component scores for dairy and fatty acids at 16-wk post-intervention.

CONCLUSION

The FMNCP did not significantly improve diet quality among adults with low incomes over the study period. Further research is needed to explore whether higher subsidy amounts or a longer intervention period is needed to meaningfully improve diet quality among adults with low incomes. This trial was registered at [clinicaltrials.gov] as [NCT03952338].

Systematic review on fiscal policy interventions in nutrition

Introduction

Both the World Health Organization and the Lancet Series on Adolescent nutrition recommend that governments adopt fiscal policies to combat diet-related non-communicable diseases (NCDs). However, rigorous, systematic evidence regarding the effects of these interventions is lacking.

Methods

We synthesize the available evidence regarding the impacts of taxes and subsidies that directly affect consumer prices on availability and accessibility of foods and beverages, purchasing behavior, diet quality, health and well-being outcomes as well as considerations for implementation, sustainability and equity.

Results

Our initial search returned 2,113 de-duplicated studies, and ultimately 24 impact evaluations and two systematic reviews met final eligibility criteria and represented unique evaluations. Our meta-analysis of these studies suggests that taxes may decrease purchases of taxed beverages (SMD = -0.14 [95% CI: -0.29 to -0.07], n = 15). Results should be interpreted cautiously due to considerable heterogeneity (Q(14) = 335.19, p = 0.01,τ ^ 2 = 0.03 , I 2 = 95.82%).

Discussion

The evidence base is too limited to draw conclusions about the effects of taxes on beverages and calorie-dense foods on purchases, or on the effects of subsidies on purchasing or diet quality. Overall, the evidence base is inconclusive on whether fiscal policies can meaningfully influence the availability and accessibility of foods and beverages, diet quality, and health outcomes. Policymakers implementing fiscal policies should consider information campaigns on health benefits and health risks associated with certain food and beverage consumption. For taxes, exposure to health information may amplify signaling effects of taxes and reduce avoidance behaviors, such as cross-border shopping. Future evaluations should diversify data sources to better understand impacts on diet and health outcomes.

Association between niacin and mortality among patients with cancer in the NHANES retrospective cohort

Background

The vitamin niacin is used as a lipid-regulating supplement, but it is unknown whether niacin has a positive influence on cancer prognosis. In this study, we examine the relationship between niacin intake and mortality among patients with cancer.

Methods

Our study utilized all available continuous data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014. Multivariable Cox regression models were applied in order to investigate dietary niacin intake’s association with mortality. We compared the survival probability between groups of low and high niacin intake by plotting Kaplan-Meier curves. An analysis of subgroups was used to investigate heterogeneity sources.

Results

A total of 3504 participants were included in the cohort, with 1054 deaths. One thousand eight hundred forty-seven participants (52.3%) were female, 2548 participants (73.4%) were white, and the mean age (SE) was 65.38 years (0.32). According to multivariate logistic regression analysis, niacin intake was negatively associated with mortality outcomes in patients with cancer, with P values below 0.05 in all models. In subgroup analyses based on sex, age, and BMI, the association persisted. The Kaplan-Meier curves indicate that high niacin intake groups have better survival rates than low intake groups. Niacin supplementation improved cancer mortality but not all-cause mortality.

Conclusion

According to our study, higher dietary niacin intake was associated with lower mortality in cancer patients. Niacin supplements improved cancer survival rates, but not all causes of mortality.