Is the public sweet on sugary beverages? Social desirability bias and sweetened beverage taxes

A scoping study on the social determinants of health and sugar consumption in the context of policy approaches for improving population health

OBJECTIVES

To conduct a scoping review of existing research on the social determinants of health, sugar consumption and public health policy responses to address or improve health outcomes.

METHODS

A total of 13 categories were developed to reflect the authors' interest in the overall focus on the social determinants of health, sugar as an independent risk factor, upstream policy action ('whole populations'), downstream policy action ('targeted') and two contemporary policy strategies (namely 'Vulnerable populations' and 'Proportionate Universalism'). The search strategy was then performed on MEDLINE (via Ovid) and Web of Science, and was limited to the English language. No time limits prior to when the database search was conducted in 2022 were set to explore the full extent of the literature in this field.

RESULTS

Five hundred and sixty articles were retrieved, of which 181 met the criteria for review. When all categories were applied, the findings showed that 76% of papers focusing on sugar consumption as a risk factor for non-communicable diseases (NCDs) mentioned the social determinants of health. The majority of studies (60%) recommended downstream interventions, with 40% recommending 'upstream' interventions. A limited proportion (12%) of research work was published in dental journals. Research had been done using predominantly quantitative methods (66% of articles), with 24% of studies adopting a mixed methods approach, and 8% being exclusively qualitative. Research on contemporary strategies for sugar reduction were focused on the 'Global North' and 98% of papers used individual level data focused on targeted approaches, highlighting that there is little direct evidence for contemporary strategies aimed at reducing sugar consumption.

CONCLUSIONS

Whilst the majority of public and dental health research argues that there is a need to address the social determinants of health, the findings from this study highlight that very few empirical studies have been designed to directly inform contemporary strategies for sugar reduction. More research is therefore needed that can directly assess the evidence for contemporary strategies in public health policy.

Evaluation of the sugar-sweetened beverage tax in Oakland, United States, 2015-2019: A quasi-experimental and cost-effectiveness study

BACKGROUND

While a 2021 federal commission recommended that the United States government levy a sugar-sweetened beverage (SSB) tax to improve diabetes prevention and control efforts, evidence is limited regarding the longer-term impacts of SSB taxes on SSB purchases, health outcomes, costs, and cost-effectiveness. This study estimates the impact and cost-effectiveness of an SSB tax levied in Oakland, California.

METHODS AND FINDINGS

An SSB tax ($0.01/oz) was implemented on July 1, 2017, in Oakland. The main sample of sales data included 11,627 beverage products, 316 stores, and 172,985,767 product-store-month observations. The main analysis, a longitudinal quasi-experimental difference-in-differences approach, compared changes in beverage purchases at stores in Oakland versus Richmond, California (a nontaxed comparator in the same market area) before and 30 months after tax implementation (through December 31, 2019). Additional estimates used synthetic control methods with comparator stores in Los Angeles, California. Estimates were inputted into a closed-cohort microsimulation model to estimate quality-adjusted life years (QALYs) and societal costs (in Oakland) from 6 SSB-associated disease outcomes. In the main analysis, SSB purchases declined by 26.8% (95% CI -39.0 to -14.7, p < 0.001) in Oakland after tax implementation, compared with Richmond. There were no detectable changes in purchases of untaxed beverages or sweet snacks or purchases in border areas surrounding cities. In the synthetic control analysis, declines in SSB purchases were similar to the main analysis (-22.4%, 95% CI -41.7% to -3.0%, p = 0.04). The estimated changes in SSB purchases, when translated into declines in consumption, would be expected to accrue QALYs (94 per 10,000 residents) and significant societal cost savings (>$100,000 per 10,000 residents) over 10 years, with greater gains over a lifetime horizon. Study limitations include a lack of SSB consumption data and use of sales data primarily from chain stores.

CONCLUSIONS

An SSB tax levied in Oakland was associated with a substantial decline in volume of SSBs purchased, an association that was sustained more than 2 years after tax implementation. Our study suggests that SSB taxes are effective policy instruments for improving health and generating significant cost savings for society.

Public Support for the Imposition of a Tax on Sugar-Sweetened Beverages and the Determinants of Such Support in Spain

(1) Background: Taxes on sugar-sweetened beverages are an effective public health intervention, but can be difficult to implement in the absence of public support. This is the first study to analyze the Spanish population’s support for a tax on sugar-sweetened beverages. (2) Methods: We conducted a cross-sectional study of a representative sample of the Spanish adult population (n = 1002), using a computer-aided telephone interview with a questionnaire on nutritional policies. The support for the tax was calculated by the percentage of those who agreed plus those who strongly agreed with the measure. The sociodemographic determinants of support for the tax were analyzed using chi-squared test (χ2) and Poisson multiple regression models with robust variance. (3) Results: Of the participants, 66.9% supported a tax on sugar-sweetened beverages. Support for the tax was 9.2% higher (70% vs. 64.1%) when responders were first asked about support for tax relief and subsidies for healthy foods (p = 0.049). Support for the tax was 16% and 35% lower among persons reporting center and right-wing political sympathies (p < 0.01), and 16% lower among regular consumers of sugar-sweetened beverages (p = 0.01). (4) Conclusions: A clear majority of the Spanish population is in favor of imposing a tax on sugar-sweetened beverages. Awareness-raising campaigns and a policy of combining the measure with subsidies or tax cuts on healthy foods could increase the level of support among those currently against the intervention.

Measuring public opinion and acceptability of prevention policies: an integrative review and narrative synthesis of methods

Acceptability of and public support for prevention are an important part of facilitating policy implementation. This review aims to identify, summarize and synthesize the methods and study designs used to measure and understand public opinion, community attitudes and acceptability of strategies to prevent chronic noncommunicable disease (NCDs) in order to allow for examination of imbalances in methodological approaches and gaps in content areas. We searched four scientific databases (CINAHL, Embase, Ovid/MEDLINE and Scopus) for peer-reviewed, English-language studies published between January 2011 and March 2020 in high-income, democratic countries across North America, Europe and the Asia–Pacific region. Studies were included if they focused on opinions, attitudes and acceptability of primary prevention strategies and interventions addressing the key NCD risk factors of alcohol use, unhealthy diet, overweight/obesity, tobacco use and smoking, and physical inactivity. A total of 293 studies were included. Two thirds of studies (n = 194, 66%) used quantitative methods such as cross-sectional studies involving surveys of representative (n = 129, 44%) or convenience (n = 42, 14%) samples. A smaller number of studies used qualitative methods (n = 60, 20%) such as focus groups (n = 21, 7%) and interviews (n = 21, 7%). Thirty-nine studies (13%) used mixed methods such as content analysis of news media (n = 17, 6%). Tobacco control remains the dominant topic of public opinion literature about prevention (n = 124, 42%). Few studies looked solely at physical inactivity (n = 17, 6%). The results of this review suggest that public opinion and acceptability of prevention in the peer-reviewed literature is investigated primarily through cross-sectional surveys. Qualitative and mixed methods may provide more nuanced insights which can be used to facilitate policy implementation of more upstream strategies and policies to prevent NCDs.