Dementia: People who weigh more at diagnosis live longer, study finds
An analysis of 4,523 US adults links overweight and obesity at the time of a dementia diagnosis with a lower risk of death. The researchers stress this is no advice to gain weight.
Symbolic image · Photo: Bill Branson, National Cancer Institute / Wikimedia Commons, Public domain (cropped and resized)
People who are overweight or obese when they are diagnosed with dementia have a lower risk of death than those of normal weight. That is the finding of a study in the Journal of Alzheimer's Disease, reported by Bioengineer.org on 18.10.2026. First author is Virginia Chang of the NYU School of Global Public Health; the corresponding author is Yuan Zhang of Columbia University's Mailman School of Public Health.
The team analysed data on 4,523 adults aged 51 and over from the US Health and Retirement Study (1998–2022) who went on to develop dementia. Compared with normal weight, the risk of death was 16 per cent lower for overweight (BMI 25–29.9), 27 per cent lower for class 1 obesity (BMI 30–34.9) and 22 per cent lower for a BMI of 35 or more.
The study is observational, and according to Chang it does not show that gaining weight improves outcomes. She points to nutrition as a possible factor, saying it can be a big problem for people with dementia. The researchers say they tested for biases such as reverse causation and found they did not explain the link. The work was funded by the US National Institutes of Health.
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