Interventions to influence consumption of sugar-sweetened beverages

Evidence for higher intakes of sugar-sweetened beverages (SSBs) driving the risks of obesity, type 2 diabetes and cardiovascular disease is increasing. As a result, SSBs have been targeted across public health interventions worldwide, including Mexico- which has one of the highest levels of consumption of SSB and alarmingly high childhood obesity rates. This thesis aimed to determine the effectiveness of interventions and intervention’s components to reduce consumption of SSBs and to develop and implement an intervention in school-aged children in central Mexico. A systematic review and meta-analysis was undertaken to examine the impact that interventions have had to reduce SSB intake or increase water intake across all age groups. Identification and analysis of behavior change techniques used in interventions was also undertaken. Exploratory analyses on data from children in central Mexico indicated that 12% of 6 to 15 year olds met criteria for Metabolic Syndrome. Consequently, a 12-week school-based programme was developed to influence consumption of SSB through promotion of water intake. Sixteen classes in four schools were allocated to the intervention group (N= 2 schools, 8 classes) or control group (N= 2 schools, 8 classes). Participants were 337 children aged 7-12 years (222 in intervention and 115 in controls). Pooled estimates from meta-analyses indicated that interventions modestly influence SSB intakes in children (-92 mL/day (95% confidence interval [CI] -145 to -39; 18 studies, P<0.01) but not in adolescents (-52 mL/ day, 95% CI -121 to 17; 4 studies, P = 0.14) or in adults (-23 mL/day, 95% CI -56 to 9; 7 studies, P = 0.16). Pooled estimates of water intakes were only possible for interventions in children and these were indicative of increases in water intake (MD +80 mL/day, 95% CI 6 to 155; 6 studies, P = 0.04). There was some evidence to suggest model/demonstrating the behaviour or parental involvement helped to reduce SSB intake. Results from the study in Mexico highlighted that intervention and control groups achieved reductions in daily intake of SSB by -61 mL/day and -132 mL/day, respectively, with the difference between groups not being statistically significant (71 mL/day; 95% CI: 94 to 236; p=0.4]. Consumption of water throughout the day decreased in both groups (Intervention: -169 mL/day; 95% CI: -275 to -62 vs controls: 235 mL/day; 95% CI: -369 to -102). Information from a process evaluation highlighted difficulties in children and staff to deliver and adhere to activities as planned. In conclusion, community-level interventions can influence positive changes in consumption of SSB in children but not in adolescents or adults; an educational and environmental approach focusing on the promotion of water intake in Mexican children was insufficient to improve consumption patterns of SSB and water. Interventions in the future could potentially be benefitted by longer implementation as well as parental involvement.