Obesity, insufficient physical activity and life expectancy across 172 countries: a longitudinal ecological panel...

Area of Science:

• Global Health
• Epidemiology
• Public Health Policy

Background:

• Obesity and physical inactivity are significant global health risks.
• Their population-level impacts on life expectancy may be interconnected due to socio-economic and epidemiological transitions.

Purpose of the Study:

• To compare the strength and robustness of associations between adult obesity prevalence and insufficient physical activity with life expectancy at birth.
• Utilizing a longitudinal ecological panel of countries for analysis.

Main Methods:

• Analysis of annual country-level data from 2000-2020 (3,365 observations from 172 countries).
• Life expectancy at birth as the outcome, with adult obesity prevalence and insufficient physical activity as main exposures.
• Employed fixed-effects models, lagged exposures, country-specific time trends, and sensitivity analyses for robustness.

Main Results:

• Standalone models showed inverse associations for both obesity and insufficient physical activity with life expectancy.
• In joint models, obesity remained significantly associated with lower life expectancy, while insufficient physical activity did not.
• Sensitivity analyses, including non-linear and time-lagged models, consistently supported obesity's robust inverse association.

Conclusions:

• Adult obesity prevalence demonstrated a more robust inverse association with life expectancy at birth compared to insufficient physical activity.
• Obesity may serve as a cumulative indicator of various factors influencing population longevity, rather than a sole causal agent.
• Findings highlight the complex interplay of metabolic, social, environmental, and policy factors in shaping population health outcomes.