Sleep deprivation linked to brain connectivity changes and modest weight gain, studies show

A Neurobiology of Aging study of more than 1,300 participants found that poor sleep alters brain network communication differently across age and sex. Younger adults showed hyper‑connectivity in motor‑related regions, while adults over 65, especially women, exhibited reduced connectivity in movement areas and heightened communication between memory‑related networks, a pattern resembling early Alzheimer's changes and associated with poorer memory test performance.

A separate Columbia University trial involving 95 healthy adults reduced nightly sleep by 90 minutes for six weeks. Participants gained an average of 450 grams, were 17 minutes more sedentary each day, and showed early metabolic disturbances: women at cardiometabolic risk developed increased insulin resistance, and both sexes showed inflammatory markers in the heart. Researchers suggest that even modest chronic sleep loss can affect weight, metabolism, and brain health.

Both studies underline the public‑health relevance of adequate sleep for cognitive function and metabolic risk.