MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge, United Kingdom.
Population Health Innovation Lab, Department of Public Health, Environment and Society, London School of Hygiene and Tropical Medicine, London, United Kingdom.
PLoS Med. 2023 Jan 26;20(1):e1004160. doi: 10.1371/journal.pmed.1004160. eCollection 2023 Jan.
Sugar-sweetened beverages (SSBs) are the primary source of dietary added sugars in children, with high consumption commonly observed in more deprived areas where obesity prevalence is also highest. Associations between SSB consumption and obesity in children have been widely reported. In March 2016, a two-tier soft drinks industry levy (SDIL) on drinks manufacturers to encourage reformulation of SSBs in the United Kingdom was announced and then implemented in April 2018. We examined trajectories in the prevalence of obesity at ages 4 to 5 years and 10 to 11 years, 19 months after the implementation of SDIL, overall and by sex and deprivation.
Data were from the National Child Measurement Programme and included annual repeat cross-sectional measurement of over 1 million children in reception (4 to 5 years old) and year 6 (10 to 11 years old) in state-maintained English primary schools. Interrupted time series (ITS) analysis of monthly obesity prevalence data from September 2013 to November 2019 was used to estimate absolute and relative changes in obesity prevalence compared to a counterfactual (adjusted for temporal variations in obesity prevalence) estimated from the trend prior to SDIL announcement. Differences between observed and counterfactual estimates were examined in November 2019 by age (reception or year 6) and additionally by sex and deprivation quintile. In year 6 girls, there was an overall absolute reduction in obesity prevalence (defined as >95th centile on the UK90 growth charts) of 1.6 percentage points (PPs) (95% confidence interval (CI): 1.1, 2.1), with greatest reductions in the two most deprived quintiles (e.g., there was an absolute reduction of 2.4 PP (95% CI: 1.6, 3.2) in prevalence of obesity in the most deprived quintile). In year 6 boys, there was no change in obesity prevalence, except in the least deprived quintile where there was a 1.6-PP (95% CI: 0.7, 2.5) absolute increase. In reception children, relative to the counterfactual, there were no overall changes in obesity prevalence in boys (0.5 PP (95% CI: 1.0, -0.1)) or girls (0.2 PP (95% CI: 0.8, -0.3)). This study is limited by use of index of multiple deprivation of the school attended to assess individual socioeconomic disadvantage. ITS analyses are vulnerable to unidentified cointerventions and time-varying confounding, neither of which we can rule out.
Our results suggest that the SDIL was associated with decreased prevalence of obesity in year 6 girls, with the greatest differences in those living in the most deprived areas. Additional strategies beyond SSB taxation will be needed to reduce obesity prevalence overall, and particularly in older boys and younger children.
ISRCTN18042742.
含糖饮料 (SSB) 是儿童饮食中添加糖的主要来源，在贫困程度较高的地区，SSB 的消费也普遍较高，而这些地区肥胖的患病率也最高。SSB 消费与儿童肥胖之间的关联已被广泛报道。2016 年 3 月，英国宣布对饮料制造商征收两级软饮料行业税 (SDIL)，以鼓励 SSB 进行配方改革，并于 2018 年 4 月实施。我们研究了在 SDIL 实施 19 个月后，4 至 5 岁和 10 至 11 岁儿童肥胖患病率的变化情况，总体情况以及按性别和贫困程度进行了分析。
数据来自国家儿童测量计划，包括在英格兰公立小学接受接待（4 至 5 岁）和 6 年级（10 至 11 岁）的 100 多万名儿童的年度重复横断面测量。使用截断时间序列 (ITS) 分析 2013 年 9 月至 2019 年 11 月期间每月肥胖患病率数据，以估计与虚假（根据 SDIL 宣布前的趋势进行调整以考虑肥胖患病率的时间变化）相比，肥胖患病率的绝对和相对变化。2019 年 11 月，根据年龄（接待或 6 年级）以及性别和贫困五分位数进一步检查了观察到的和虚假估计值之间的差异。在 6 年级的女孩中，肥胖患病率（定义为英国 90 生长图表上的 >95 百分位）总体上绝对下降了 1.6 个百分点（PP）（95%置信区间（CI）：1.1，2.1），在最贫困的两个五分位数中降幅最大（例如，最贫困五分位数的肥胖患病率绝对下降了 2.4 个百分点（95%CI：1.6，3.2））。在 6 年级的男孩中，肥胖患病率没有变化，只有最不贫困的五分位数绝对增加了 1.6 个百分点（95%CI：0.7，2.5）。在接待儿童中，与虚假相比，男孩（0.5 PP（95%CI：1.0，-0.1））或女孩（0.2 PP（95%CI：0.8，-0.3））肥胖患病率均无总体变化。本研究的局限性在于使用学校的综合多维贫困指数来评估个人社会经济劣势。ITS 分析容易受到未识别的共同干预和时变混杂的影响，我们无法排除这两种情况。
我们的研究结果表明，SDIL 与 6 年级女孩肥胖患病率的降低有关，在最贫困地区的差异最大。需要采取除 SSB 征税以外的其他策略来降低总体肥胖患病率，特别是在年龄较大的男孩和年幼的儿童中。
ISRCTN84503564.
