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 Chinese people without high blood pressure who are obese (BMI 28 or higher) do not have a significantly different risk of dying from any cause compared to those with a normal weight.

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.

Older Chinese people without high blood pressure who are overweight (BMI between 24 and 28) are less likely to die from any cause compared to those with a normal weight.

Older Chinese people with high blood pressure who are obese (BMI 28 or higher) are less likely to die from any cause compared to those with a normal weight.

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.