http://people.duke.edu/~mch55/resources/Harding_Nutritiondemand.pdf Page 27: "Because of the large expenditure elasticity for soda, a 20% soda tax reduces soda expenditure by 3.92% and the share of soda in the household budget by 3.43%. This reduces caloric intake by 2,231 calories and sugar intake by 675g. These changes translate to a reduction in caloric intake from soda by the equivalent of about 16 cans of Coca-Cola per month. As suggested by our results on the cross-price elasticities, soda taxes also induce a shift towards milk and snacks/candy and away from packaged meals and meat. These changes, along with a 1.66% reduction in total expenditures due to the soda tax, lead to declines in the purchase of each nutrient group. In particular, calories decline by 4.84% (4,779 calories) and sugar purchases decline by 10.35% (763.6g), the majority of which come from reductions in soda purchases. Declines in fat, salt, cholesterol, carbohydrates and protein also range from 2-4%. The expenditure and price changes from this tax lead to an average decline in indirect utility of 2.5%." This model helps show that a soda tax may lead to decreased soda consumption and to an overall decrease in sugar and calorie consumption.
The outcome of a preliminary study found a significant drop in sugar-sweetened beverages following a tax on them in Mexico. The tax was implemented on January 1, 2014, and is still in effect. The study looked at 2014 consumption and adjusted for an existing negative trend in soda consumption. http://uncfoodresearchprogram.web.unc.edu/822/ and http://www.insp.mx/epppo/blog/3666-reduccion-consumo-bebidas.html The results are preliminary. "The data comes from a commercial panel of consumers that contains information on purchases of beverages from households living in 53 cities with at least 50,000 residents. The model adjusts for the pre-existing downward trend of taxed beverages since 2012 and for macroeconomic variables that can affect purchases. Preliminary results show a 6 percent average decline in purchases of taxed beverages over 2014 compared to pre-tax trends. This difference accelerated over 2014 and the reduction compared to pre-tax trends reached 12% by December 2014. All socioeconomic groups reduced purchases of taxed beverages. Reductions were higher among lower socio-economic households, averaging 9% decline over 2014 compared to pre-tax trends and up to a 17% decline by Dec 2014. Results also show roughly a 4 percent increase in purchases of untaxed beverages over 2014, mainly driven by an increase in purchased bottled plain water (tap water intake is not collected)." Will update node as more data on Mexican beverage-drinking habits are released.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3628978/pdf/nihms-428475.pdf Page 5: "We estimated that substituting one cup/d of water for one serving/d of SSBs was associated with 0.49 kg (95% CI: 0.32, 0.65) less weight gain within each 4-year period (Figure 1), and the substitution estimate of water for fruit juices was 0.35 kg (95% CI: 0.23, 0.46). Substitution of coffee for SSBs or fruit juices was associated with similar magnitudes of less weight gain (0.50 and 0.36 kg, respectively). Replacements of tea (0.39 and 0.25 kg), diet beverages (0.47 and 0.33 kg), and low-fat milk (0.34 and 0.20 kg) for SSBs or fruit juices were all significantly and inversely related to weight gain (Figure 1)."
http://www.ncbi.nlm.nih.gov/pubmed/20693348 Meta-analysis of 11 studies. Defined sugar-sweetened beverages as including soft drinks, fruit drinks, iced tea, and energy and vitamin water. "Based on data from these studies, including 310,819 participants and 15,043 cases of type 2 diabetes, individuals in the highest quantile of SSB intake (most often 1-2 servings/day) had a 26% greater risk of developing type 2 diabetes than those in the lowest quantile (none or <1 serving/month) (relative risk [RR] 1.26 [95% CI 1.12-1.41])." Note that these results are comparing the highest and lowest quintiles, the results are between two potentially very disparate groups.
http://www.nejm.org/doi/full/10.1056/NEJMoa1203039#t=articleResults Under the results section: "Numerous studies have shown a positive association between the intake of sugar-sweetened beverages, obesity, and related cardiometabolic diseases.6-11 As reported elsewhere in this issue of the Journal, two randomized intervention studies show that a reduction in the consumption of sugar-sweetened beverages and a replacement of sugar-sweetened beverages with noncaloric sweetened beverages reduced weight gain in children.38,39 Although further evidence is warranted, these data support a causal relationship among the consumption of sugar-sweetened beverages, weight gain, and the risk of obesity. The current finding that the genetic effects on adiposity are stronger in persons with higher intake than in those with lower intake provides useful information on the role of sugar-sweetened beverages in triggering obesity; increased consumption might contribute to the obesity epidemic by interacting with a genetic predisposition to elevated BMI. From another perspective, persons with a greater genetic predisposition may be more susceptible to obesity-inducing effects of sugar-sweetened beverages."
http://circ.ahajournals.org/content/early/2012/03/09/CIRCULATIONAHA.111.067017.full.pdf+html Page 11: "In this study, consumption of sugar-sweetened beverages was significantly associated with an increased risk of CHD. This was after adjusting for multiple lifestyle-related factors including overall diet quality and BMI, which were strong risk factors for CHD. We also adjusted for prior weight change and dieting, which could motivate participants to switch from 12 sugar- to artificially sweetened beverages. 30 For a one serving per day increase in sugarsweetened beverage intake, the risk of CHD increased by 19% (RR = 1.19, 95% CI: 1.11, 1.28, p < 0.01). Similar results were observed in the Nurses’ Health Study (n = 88 520, cases = 3105, follow-up = 24 y), where a 1 serving per day increase in sugar-sweetened beverage intake was associated with a 15% increase in risk (RR = 1.15, 95% CI: 1.07, 1.20, p < 0.01).4 The average baseline intake of sugar-sweetened beverages was slightly higher in the Nurses’ Health Study (0.41 servings / day) than in the Health Professionals Follow-up study. (0.36 servings / day)4 Our results were stable after a number of sensitivity analyses."
http://www.healthpolicyjrnl.com/article/S0168-8510(10)00224-1/abstract Analysis of Canadian Community Health Survey. From the abstract: "In 2005 an estimated 1.3 million Canadians (4.9%) reported having diabetes. The prevalence of T2DM in the lowest income group is 4.14 times higher than in the highest income group. Prevalence of diabetes decreases steadily as income goes up. The likelihood of diabetes was significantly higher for low-income groups even after adjusting for socio-demographic status, housing, BMI and physical activity. There is a graded association between income and diabetes with odds ratios almost double for men (OR 1.94, 95% CI 1.57–2.39) and almost triple for women (OR 2.75 95% CI 2.24–3.37) in the lowest income compared to those in highest income."
http://ije.oxfordjournals.org/content/40/3/804 Looked at studies across multiple nations that covered socioeconomic position and diabetes incidence. From the abstract: "Relevant case–control and cohort studies published between 1966 and January 2010 were searched in PubMed and EMBASE using the keywords: diabetes vs educational level, occupation or income. All identified citations were screened by one author, and two authors independently evaluated and extracted data from relevant publications. Risk estimates from individual studies were pooled using random-effects models quantifying the associations. Out of 5120 citations, 23 studies, including 41 measures of association, were found to be relevant. Compared with high educational level, occupation and income, low levels of these determinants were associated with an overall increased risk of type 2 diabetes; [relative risk (RR) = 1.41, 95% confidence interval (CI): 1.28–1.51], (RR = 1.31, 95% CI: 1.09–1.57) and (RR = 1.40, 95% CI: 1.04–1.88), respectively. The increased risks were independent of the income levels of countries, although based on limited data in middle- and low-income countries."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2848262/ From the discussion section: A socioeconomic gradient exists in diabetes-related mortality in the U.S., with both education and income being important determinants of the risk of death associated with this disease. In models adjusted for age, sociodemographic characteristics, and BMI, adults with less than a high school education had a risk of diabetes-related mortality that was twice that of those with a college degree, and those living in poverty had a risk that was 2.4 times that of those with an income ?400% FPL. However, the increased risk was not present just for those with the lowest SES, but rather an increased risk for diabetes-related mortality existed for all levels of education compared with adults who had a college degree and all levels of income compared with adults with family incomes ?400% FPL.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2329746/ From results: "The proportions of U.S.-born blacks, Puerto Ricans, and Mexicans/Mexican-Americans who reported consuming more than one soda per day was more than twice that of whites. Individuals aged 18–24, men, and those with less than a college education were also more likely to be frequent soda consumers. In addition, those living in households with an income of 200% of the poverty level or less were more likely to be frequent soda consumers than those from higher income households. The prevalence of frequent soda consumption was highest among obese and overweight individuals, compared to normal weight individuals. "