Overweight or obese women aged 50 to 79 who consumed all their daily calories within an 8-to-9-hour window showed significant improvements in spatial planning and problem-solving compared with those who ate over a typical 12-hour period, according to a small clinical trial presented at the American Nutrition Society’s annual meeting, NUTRITION 2026. Both groups reduced their intake by 500 calories a day and lost an average of 7 kg over six months, yet the cognitive gains were seen only in the time-restricted group.

The 26 women in the time-restricted arm, who generally ate between 10 a.m. and 6 p.m., also tended to make fewer errors on memory and learning tests, though that difference did not reach statistical significance. No meaningful differences emerged in multitasking ability or reaction time.

Sue Shapses, a professor at Rutgers University and the study’s senior author, said the data suggest that stopping food intake four hours before bedtime and compressing the eating window may confer cognitive benefits beyond those of weight loss alone. The findings are especially relevant for women and individuals with excess weight, who face a higher risk of Alzheimer’s disease and other dementias.

The trial involved only 47 participants, and the researchers stressed that larger studies are required to confirm the results. They plan to investigate possible biological mechanisms, including the interplay of circadian rhythms, nutrient-sensing pathways, inflammation, and metabolic health. The work is preliminary and has not yet been published in a peer-reviewed journal.