Restricted eating window may slow cognitive decline, pilot study suggests
13 reported2 unconfirmed
A small pilot study presented at a nutrition conference suggests that confining meals and snacks to a nine-hour window and avoiding food for four hours before bed may help reduce cognitive decline in older age. Researchers at Rutgers University studied 47 women aged 50 to 79 who were living with overweight or obesity, encouraging all to cut 500 calories daily for six months. Within the group, 26 women were advised to eat only within a nine-hour window, typically between 10am and 6pm, while the rest spread meals over about 12 hours. Both groups lost an average of 7kg, but cognitive tests showed those in the restricted-eating window performed better on spatial planning and problem solving tests. The lead researcher called the effects “modest” and noted hints of fewer errors on memory and learning tests, though multitasking and reaction time results were similar between groups. The findings are preliminary due to the small trial size, and researchers plan to investigate the role of circadian rhythms, metabolism, and inflammation. An independent expert cautioned that the full peer-reviewed study is needed to determine if the improvements are clinically meaningful.
What’s reported
The pilot study involved 47 women aged 50 to 79 living with overweight or obesity.
All participants were encouraged to cut 500 calories from their daily diet for six months.
26 women were advised to eat only within a nine-hour window, typically 10am to 6pm.
The rest of the volunteers spread their meals over about 12 hours.
Both groups had similar weight loss averaging about 7kg.
Cognitive tests showed those in the restricted window performed better on spatial planning and problem solving tests.
There were hints of fewer errors on memory and learning tests for the restricted-eating group.
On some multitasking and reaction time tests, both groups performed the same.
The lead researcher, Prof Sue Shapses, called the effects “modest.”
Details were presented at Nutrition 2026, the annual meeting of the American Society for Nutrition in Maryland.
Dementia is the leading cause of death in the UK and seventh worldwide, causing nearly 2 million deaths globally each year.
Obesity in middle age can raise the risk of dementia in later life by 30%.
A review published in January found finishing eating before 7pm was associated with improvements in body weight, BMI, waist circumference, blood pressure, and metabolic health markers.
Open questions
Whether the cognitive improvements observed are clinically meaningful.
Why time-restricted eating may benefit cognitive health; researchers plan to investigate circadian rhythms, metabolism, and inflammation.
Key figures
Prof Sue Shapses, nutritional scientist at Rutgers University, New Jersey, US
Prof Wendy Hall, head of nutritional sciences at King’s College London (not involved in the study)
Sources: The Guardian
