The good news: People around the world are living longer. The not-so-good news? That doesn't necessarily mean they're living healthier lives. In the newly released Global Burden of Disease Study 2010, published in the Lancet and funded by the Bill & Melinda Gates Foundation, 486 researchers from 302 institutions worldwide put together "the most detailed look at health on the population level ever attempted," says David Brown at the Washington Post

The main takeaway? Childhood mortality rates have declined 60 percent worldwide between 1990 and 2010, and average life spans have correspondingly lengthened. At the same time, more people are spending large chunks of their twilight years living with disabilities (mental disorders, musculoskeletal pain, vision loss, hearing loss, among others) — an average of 9.2 years for men, and 11.5 years for women. "We are in transition to a world where disability is the dominant concern as opposed to premature death," said Christopher J.L. Murray of the University of Washington, who led the study.

Which country's citizens were the least susceptible to disease, had the best health care, and lived the longest, most comfortable lives? Unsurprisingly, Japan — for both men and women. "No one knows whether it's their great diet, good health care, or just great genes," says Dr. Lauren Browne at ABC News, "but after two decades the Japanese are still the healthiest people in the world." The United States tied with Norway for 29th place in male healthy life expectancy rankings, and for females, tied with Estonia for 33rd place. Here's how the Top 10 countries break down for both males and females:

Highest male healthy life expectancies

1. Japan
2. Singapore
3. Switzerland
4. Spain
5. Italy
6. Australia
7. Canada
8. Andorra
9. Israel
10. South Korea

Highest female healthy life expectancies

1. Japan
2. South Korea
3. Spain
4. Singapore
5. Taiwan
6. Switzerland
7. Andorra
8. Italy
9. Australia
10. France

Sources: ABC News, Guardian, Washington Post, WHO