Restricted eating hours may reduce cognitive decline in older age, researchers find
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- Prof Sue Shapses of Rutgers University ran a 6-month clinical trial with 47 women aged 50–79 living with overweight or obesity, all asked to cut 500 calories daily; 26 were additionally told to eat only between roughly 10am and 6pm.
- Both groups lost an average of about 7kg (15lbs), but the time-restricted group outperformed the longer-eating group on spatial planning and problem-solving cognitive tests, with hints of fewer errors on memory and learning measures.
- On multitasking and reaction time tests the two groups performed the same, and Shapses called the overall effects "modest," with results presented at Nutrition 2026, the American Society for Nutrition's annual meeting in Maryland.
- Prof Wendy Hall of King's College London, who was not involved in the trial, said time-restricted eating is a "plausible approach" to supporting cognitive health in midlife and older adults with overweight, citing potential benefits for blood sugar control, vascular function and inflammation, but cautioned the findings are preliminary pending peer review.
- Context cited in the article: nearly half of dementia cases worldwide could be prevented or delayed through lifestyle changes, and obesity in middle age is linked to a 30% higher risk of dementia in later life.
- A review published in January found that finishing eating before 7pm was associated with improvements in body weight, BMI, waist circumference, blood pressure and metabolic health markers, even though eating over a 14-hour window is common in the UK and US.
Why it matters: Dementia is the leading cause of death in the UK and the seventh worldwide, killing nearly 2 million people globally each year, and the trial adds to a small but growing body of evidence that *when* people eat may matter for brain health independent of how much they weigh. The researchers plan next to probe the circadian-rhythm, metabolic and inflammatory mechanisms behind the cognitive edge seen in the 9-hour-window group.
