RAND Corporation, Santa Monica, California.
Centro de Investigación y Docencia Económicas, Santa Fe, Mexico City, Mexico.
JAMA Pediatr. 2022 Feb 1;176(2):150-158. doi: 10.1001/jamapediatrics.2021.5044.
Following the implementation of a tax on sugar-sweetened beverages (SSBs) in Mexico in 2014, SSB prices increased by about 10% on average, but differently across cities. It remains unclear how observed SSB price changes are associated with adolescent weight-related outcomes.
To compare weight-related outcomes among adolescents living in cities with differential SSB price changes before and after the SSB tax was implemented in Mexico.
DESIGN, SETTING, AND PARTICIPANTS: Associations between differential SSB price changes and changes in weight-related outcomes were examined overall and by sex among 12 654 adolescents aged 10 to 18 years born between 1999 and 2002 living in 39 cities in Mexico. Multivariate regressions with individual fixed effects were applied on longitudinal individual-level yearly clinical data (height and weight) from 2012 to 2017 collected by the Instituto Mexicano del Seguro Social (IMSS) and merged with city-level SSB price data from 2011 to 2016 collected by the National Institute of Statistics and Geography (INEGI). Data were analyzed from July 2018 to July 2021.
Yearly city-level changes in SSB prices between 2011 and 2016.
Age- and sex-specific body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) percentile and indicator for overweight or obesity if BMI was at or above the 85th percentile.
Before 2014, 46% of 12 654 adolescents (6850 girls and 5804 boys) included in this study had obesity or overweight. The mean (SD) age was 11.38 (1.08) years. Among girls, a 10% SSB price increase was associated with a 1.3 percentage point absolute decrease (95% CI, -2.19 to -0.36; P = .008) or a 3% relative decrease in overweight or obesity prevalence within 2 years of a price change. For girls with BMI at or above the 75th percentile pretax, this price increase was associated with a 0.59 lower BMI percentile (95% CI, -1.08 to -0.10; P = .02) or a 0.67% relative decrease. Improved outcomes for girls were observed in cities where price increases were greater than 10% after the tax. No such associations were observed for boys.
In this study, increased SSB prices were associated with decreased overweight or obesity prevalence among girls but not among boys. Improvements in outcomes were small, and mostly observed for girls with heavier weight and in cities where price increases after the tax were greater than 10%.
重要性：2014 年墨西哥实施含糖饮料（SSB）税后，SSB 价格平均上涨约 10%，但不同城市的涨幅不同。目前尚不清楚观察到的 SSB 价格变化与青少年体重相关结果之间的关系。
目的：比较实施 SSB 税后，在墨西哥不同城市 SSB 价格发生变化前后，青少年体重相关结果的差异。
设计、地点和参与者：在墨西哥 39 个城市，对 12654 名 10 至 18 岁的青少年（1999 年至 2002 年出生）进行了总体比较，并根据性别比较了 SSB 价格变化与体重相关结果之间的差异。采用个体固定效应的多元回归，对 2012 年至 2017 年由墨西哥社会保障研究所（IMSS）收集的纵向个体水平年度临床数据（身高和体重）进行分析，并与 2011 年至 2016 年由国家统计和地理研究所（INEGI）收集的城市 SSB 价格数据进行合并。数据分析于 2018 年 7 月至 2021 年 7 月进行。
暴露：2011 年至 2016 年期间，城市层面 SSB 价格的年度变化。
主要结果和测量：按年龄和性别划分的体重指数（BMI；体重以千克为单位，身高以米为单位）百分位数，以及 BMI 处于或高于第 85 百分位时超重或肥胖的指标。
结果：在 2014 年之前，这项研究中包括的 12654 名青少年（6850 名女孩和 5804 名男孩）中，有 46%患有肥胖症或超重。平均（SD）年龄为 11.38（1.08）岁。在女孩中，SSB 价格上涨 10%，与超重或肥胖的流行率在 2 年内绝对下降 1.3 个百分点（95%CI，-2.19 至-0.36；P=0.008）或相对下降 3%有关。对于税前 BMI 处于或高于第 75 百分位的女孩，这种价格上涨与 BMI 百分位下降 0.59（95%CI，-1.08 至-0.10；P=0.02）或相对下降 0.67%有关。在税收后价格涨幅超过 10%的城市，女孩的结果得到了改善。但男孩没有观察到这种关联。
结论：在这项研究中，SSB 价格上涨与女孩超重或肥胖的流行率下降有关，但与男孩无关。结果的改善很小，主要是在体重较重的女孩和税收后价格涨幅超过 10%的城市中观察到的。
