BACKGROUND: In response to increasing overweight and obesity, the Philippine government introduced a tax on sweetened beverages (SBs) in 2018. Evidence suggests that the beverage industry influenced the final tax design, making it more favourable for industry than the initially proposed bill. This study aimed to compare the relative health and economic benefits of the proposed SB tax with the implemented SB tax. METHODS: Philippine dietary consumption data were combined with price elasticity data from Mexico and data from Australia adapted to the Philippine context to estimate reductions in SB purchases and changes in body mass index (BMI) following the implementation of the tax. A multi-state, multiple-cohort Markov model was used to estimate the change in health-adjusted life years (HALYs) due to reduction in the epidemiology of obesity-related diseases, healthcare cost savings and government taxation revenue, resulting from both the proposed and implemented tax policies, over the lifetime of the 2018 Philippine population. FINDINGS: The proposed and implemented taxes were modelled to be dominant (cost-saving and improving health). Intervention costs were modelled to be PHP305.2 million (M) (approximately US$6M). Compared to the proposed tax, the implemented tax was modelled to result in a 43.0% smaller reduction in targeted beverage intake (51.1 ml/person/day vs. 89.7 ml/person/day), a 43.5% smaller reduction in BMI (0.35 kg/m2 vs. 0.62 kg/m2), 39.7% fewer HALYs gained (2,503,118 vs. 4,149,030), 39.9% fewer healthcare cost savings (PHP16.4 billion (B) vs. PHP27.3B), and 27.7% less government taxation revenue (PHP426.3B vs. PHP589.4B). INTERPRETATION: While the implemented tax in the Philippines will benefit population health, it is likely to yield less benefit than the proposed tax. The influence of the food and beverage industry on policy processes has the potential to lessen the benefits of population NCD prevention policies. FUNDING: OH was supported to conduct this research by an Australian Government Research Training Program Stipend Scholarship. The funding body had no role in data collection and analysis, or manuscript preparation.