Article Text
Abstract
Background Growing evidence suggests that sugar sweetened beverage (SSB) intake can increase long-term weight gain and hence worsen the ongoing obesity epidemic. A tax on SSBs might offer an effective population wide intervention to reduce the burden of obesity, cardiovascular diseases (CVD) and common cancers. We aimed to estimate the potential impact on obesity of a 10% and 20% tax on SSBs in Turkey.
Methods We developed a Markov model for the Turkish population aged 35 years and older. The model follows a closed cohort from year 2011 to 2031. The cohort has the probability of transition to healthy, overweight or obese states or to die from CVD, cancer or other causes. Model inputs were population and death records from Turkish Statistical Institute, overweight and obesity prevalence from Turkish National Chronic Disease Survey, 2011, daily mean SSB intake from Turkish National Diet and Nutrition Survey. We used DISMOD II software to estimate the incidence of overweight and obesity. The effect of tax was calculated using price elasticities obtained from previous published studies. We compared three scenarios: The baseline scenario involved no change in consumption of SSBs. In two additional scenarios, we modelled the effect of a 10% and 20% tax on decreasing SSBs intake. We then modelled the effect of this SSB decrease on BMI and obesity prevalence on the Turkish population. We further calculated the population attributable risk fraction of obesity to estimate the CVD and cancer cases potentially preventable. We also conducted a probabilistic sensitivity analysis to estimate 95% uncertainty intervals (95% UI).
Results We forecast that in this closed cohort, by the year 2031, approximately 4,201,100 (4,130,000–4,270,000) men and 5,419,000 (5,305,000–5,537,000) women would be obese. However implementing a 10% SSB tax could result in approximately 21,900 (19,800–29,040) fewer obese men and 13,500 (12,900–15,400) fewer obese women. A 20% tax might result in 41,900 (40,100–48,100) fewer obese men and 24,800 (15,600–28,700) fewer obese women. Overall, a 20% tax could result in a 0.7% reduction in obesity prevalence in the whole cohort. This might result in approximately 29,700 fewer CVD cases and 13,400 fewer obesity related cancer cases by 2031.
Conclusion A tax on Sugar Sweetened Beverages in the Turkish population could usefully reduce the prevalence of obesity, cardiovascular disease and common cancers. These findings reinforce the growing evidence of health benefits with SSB taxation policies in diverse countries.