Older adults who lose more than 5% of their body weight are more likely to die within the study period compared to those whose weight stays stable.

People who are too thin have a much higher chance of dying early—even more than those who are obese—suggesting being underweight is just as dangerous as being very overweight.

Being underweight, overweight, or obese at the start of the study didn't significantly change the risk of death compared to having a normal weight in older adults.

Older adults who lose more than 5% of their waist size are more likely to die within the study period compared to those whose waist size stays stable.

Older Chinese people with high blood pressure who are underweight (BMI below 18.5) are slightly more likely to die from any cause, but this difference is not statistically significant compared to those with normal weight.