# Estimating the effect on obesity of delaying tax-based interventions in Mexico: A modeling study

## TL;DR

This study models how delaying tax increases on sugary drinks and unhealthy foods in Mexico affects obesity rates and deaths by 2040.

## Contribution

The study quantifies, for the first time, the health and mortality consequences of delaying tax-based obesity interventions in Mexico.

## Key findings

- Doubling taxes in 2025 could avert 170,600 deaths and add 25 million healthier life years by 2040.
- Delaying tax doubling until 2035 results in 38,900 deaths averted and 4.5 million healthier life years gained.
- Obesity prevalence by 2040 is projected to be 41.6% if taxes are doubled in 2025, versus 44.5% under the status quo.

## Abstract

The World Health Organization (WHO) launched the Acceleration Plan to STOP Obesity, highlighting the urgent need for timely implementation of proven interventions. Fiscal policies, including taxes on sugar-sweetened beverages (SSB) and non-essential energy-dense foods (NEDF), are among the most cost-effective strategies to reduce obesity rates. Delays in adopting or strengthening these measures can undermine their impact, and the consequences of postponing such policies remain unmeasured. We aimed to estimate the expected impact of delaying doubling the SSB and NEDF tax in Mexico.

We simulated a closed cohort of Mexican adults aged 20 years and over from 2021 to 2040. The simulated sample corresponded to the combination of the 2020−22 Health and Nutrition Surveys, which contained anthropometric and demographic information representative at a national level. We projected annual average Body Mass Index (BMI), obesity prevalence, deaths averted, and years lived without obesity (YLWO) under four scenarios: status quo and doubling the current tax on SSB and NEDF in 2025, 2030, and 2035. BMI was projected from 2021 to 2040 using Hall’s microsimulation weight change model, and a Mexican projection of total energy intake. To simulate deaths, we estimated the probability of all-cause mortality by BMI category from the National Population Council projections of the Mexican population by age and year. By 2040, doubling the taxes in 2025 resulted in an obesity prevalence of 41.6% (95% Uncertainty Interval [40.2,43.1]) in contrast to the status quo scenario (44.5%, 95% Uncertainty Interval [43.2,45.8]), and 170,600 deaths averted (95% Uncertainty Interval [130,900, 210,200]) and 25,031,900 (95% Uncertainty Interval [19,048,500, 31,015,300]) YLWO gained. A delayed intervention in 2035 resulted in an obesity prevalence of 41.7% (95% Uncertainty Interval [40.4,43.1]), 38,900 deaths averted (95% Uncertainty Interval [29,600, 48,200]), and 4,473,700 (95% Uncertainty Interval [3,378,900, 5,568,500]) YLWO gained. Our results apply only to individuals aged 20 years or older in 2021, excluding cohorts reaching age 20 between 2022 and 2040.

Our results emphasize the urgency of advancing WHO’s Acceleration Plan to STOP Obesity. Postponing evidence-based interventions is estimated to exacerbate the burden of obesity, mortality, and suffering.

Structural interventions to control obesity, such as unhealthy food and beverage taxes, are available and cost-effective. Yet, they are subject to significant delays in approval and implementation.

Mexico led the implementation of taxes on sugar-sweetened beverages (SSB) and non-essential energy-dense foods (NEDF). Still, despite recommendations to double taxes since 2018, no action has been taken.

Delays in the implementation of structural interventions to control obesity have important impacts, but these are rarely discussed or estimated. Thus, we aimed to estimate the cost in terms of years lived without obesity and deaths of delaying doubling health taxes in Mexico.

Using national data from Mexican adults, we modeled the impact of waiting to double existing taxes on SSB and NEDF. We simulated the Mexican adult population and compared what would happen if taxes were doubled in 2025, 2030, or 2035.

Doubling the taxes in 2025 could prevent more than 170,000 deaths and add 25 million healthier life years by the year 2040, compared to waiting until 2035 to double the taxes.

Delaying the implementation of effective policies, such as increasing taxes on unhealthy products and beverages, has serious consequences: the longer these measures are postponed, the more people will be at risk- and die- from obesity-related diseases.

This study highlights the urgent need for policymakers to act quickly on evidence-based solutions to reduce obesity and its negative outcomes, and for scientists to consider the cost of delay when modeling potential health interventions.

Our model has important limitations. We assume that consumption trends for NEDF and SSB will slow over time, which may not reflect future real-world changes. We also do not account for the younger generation’s consumption patterns, who may respond differently to taxes.

In a modelling study, Martha Carnalla and colleagues investigate the effects doubling the current tax on sugar-sweetened beverages and non-essential energy-dense foods would have on obesity levels, by simulating a closed cohort of Mexican adults.