Overview
- Researchers analyzing 4,523 adults from the Health and Retirement Study found that being overweight or obese at the time of a dementia diagnosis was associated with lower subsequent mortality compared with normal weight.
- The study reported specific reductions in death risk of 16% for overweight (BMI 25–29.9), 27% for class 1 obesity (BMI 30–34.9), and 22% for class 2–3 obesity (BMI ≥35).
- Authors used data from 1998–2022 and ran tests for common biases, including pre-diagnostic weight loss and survivor bias, and concluded those factors did not explain the survival advantage they observed.
- Possible explanations offered include greater energy or muscle reserves that protect against later wasting and appetite loss in dementia, but the study does not establish biological cause.
- The team and funders note the work is observational and NIH-supported, so clinicians should focus on nutritional assessment and prognosis rather than advising patients to gain weight.