Time-restricted eating dementia study finds modest cognitive gains
A Rutgers-led pilot trial found older women who ate within 8–9 hours improved on some cognitive tests after six months.
By Tom Brennan · Health & Medicine Correspondent
3 min read
A small clinical trial suggests time-restricted eating may help preserve some thinking skills linked to dementia risk in older women with overweight or obesity. The findings matter because the approach produced modest cognitive gains even though participants lost about the same amount of weight as women who followed calorie cutting alone, according to the American Society for Nutrition.
Sue Shapses, a professor at Rutgers University and Rutgers-RWJ Medical Center and the trial’s principal investigator, said the results point to possible benefits from ending food intake four hours before sleep and keeping meals within an 8–9 hour daily window. Her group is presenting the work at NUTRITION 2026, the American Society for Nutrition’s annual meeting, held July 25–28 in National Harbor, Maryland.
Can time-restricted eating improve cognition?
The pilot study found significant improvement in spatial planning and problem-solving among women assigned to the shorter eating window, compared with those who kept a more typical 12-hour eating span. The time-restricted group also showed a trend toward fewer mistakes on memory and learning tests, according to the researchers.
The study did not find significant differences between the groups on multitasking or reaction-time tests. Shapses said the results suggest a modest effect and that larger studies are needed to confirm whether the eating schedule itself can help protect cognitive function.
Who took part in the trial?
The trial enrolled 47 women ages 50 to 79 who had overweight or obesity. All participants received counseling to cut their daily intake by 500 calories.
Twenty-six women were assigned to limit eating to less than nine hours each day. The remaining participants kept a standard eating window of about 12 hours a day.
Women in the time-restricted group generally ate between 10 a.m. and 6 p.m., with an average eating window of 8.2 hours. The comparison group averaged 12.3 hours a day, according to the American Society for Nutrition.
What is time-restricted eating?
Time-restricted eating is a form of meal timing in which people consume food only during a set block of hours each day. In this study, the shorter window meant eating for roughly 8–9 hours and fasting for the rest of the day, including the hours before sleep.
After six months, participants in both groups had lost about 15 pounds, or 6.8 kilograms, on average. Because weight loss was similar, the researchers said the cognitive differences may be tied to the shorter eating window rather than weight change alone.
Why researchers are studying diet and dementia risk
Alzheimer’s disease and other forms of dementia have become more common as populations age, according to the American Society for Nutrition. The organization said women and people with overweight or obesity tend to have a higher likelihood of developing these conditions.
Diet and other lifestyle factors have been associated with dementia risk, but the researchers said fewer studies have tested whether changing those factors can reduce risk. This trial was designed as an early test, not a definitive answer.
The Rutgers team plans to study possible explanations for the findings, including circadian rhythms, nutrient-sensing pathways, inflammation and metabolic health. For now, the results suggest that meal timing deserves further testing in larger groups of participants, according to the researchers.
This story draws on original reporting from Medical Xpress.