Weight loss in adults with Down syndrome and with dementia in Alzheimer's disease.

The team looked at medical records of older adults with Down syndrome. They wanted to see who lost weight as they aged. They also checked if the adults had Alzheimer’s disease.

No new treatment was given. The study simply tracked weight changes that had already happened.

Almost every older adult with Down syndrome had lost weight over time. The adults who also had Alzheimer’s lost even more weight.

Weight loss was not rare—it was the usual pattern in this group.

Older surveys painted a different picture. Rasing et al. (1992) and Sturmey (1995) showed that younger and middle-aged adults with Down syndrome are often obese. Together the papers trace an upside-down U: extra weight in mid-life, then weight loss later.

Real de Asua et al. (2014) add that belly fat in adults with Down syndrome can signal insulin trouble. The new finding does not erase that risk; it just shows the scale can tip the other way as dementia appears.

McQuaid et al. (2024) muddied the waters by reporting that obesity in middle-aged Down syndrome adults did not bring the usual metabolic harm. The 2004 data do not clash—they simply look at a later life stage when weight moves in a new direction.

If you support adults with Down syndrome, expect weight to fall after mid-life. Track weight at every visit. A sudden or steady drop can be an early red flag for Alzheimer’s disease, prompting timely cognitive screening and care planning.