McKinsey argues that longer life expectancy is increasingly paired with more years lived in poor health—and that the gap is widening. Global life expectancy is projected to reach 78 years by 2050, but the average time lived with illness has risen from about 8.7 years in 2000 to 10.2 years in 2025 and is projected to reach
The report models what happens if countries scale access to roughly 300 proven, cost-effective interventions spanning most of the global disease burden. McKinsey estimates this could avert 35% of total disease burden in 2050, prevent 33 million premature deaths, and add about nine healthy years to average healthy life expectancy—driven largely by prevention, which accounts for nearly two-thirds of the potential impact even though most countries spend less than 2% of health budgets on it. On the economic side, the report estimates $12.5 trillion in annual global economic value by 2050 (about 7% of global GDP) with an estimated 4:1 return on investment, while pointing to practical levers such as aligning incentives around prevention, coordinating action beyond healthcare, and improving health-system efficiency so more health is delivered per dollar.