Limiting meal times can support cognitive function

The study involved 47 overweight or obese women between the ages of 50 and 79, who were at increased risk of developing dementia and Alzheimer’s disease. The participants followed a weight loss program and reduced their daily calorie intake by 500 kilocalories. The women were divided into two groups: one group limited their eating to a time window of less than 9 hours per day, while the other group maintained their usual eating habits with a window of approximately 12 hours.

In practice, the participants in the restricted-eating group ate for an average of 8.2 hours, most often from 10:00 a.m. to 6:00 p.m., which means they stopped eating about four hours before bedtime. In the control group, the average duration of the eating window was 12.3 hours per day.

After six months, both groups showed comparable results in terms of weight loss, with an average reduction of about 6.8 kilograms. This allowed the researchers to evaluate the effect of reducing the time window for eating, rather than the effect of weight loss itself.

Cognitive tests revealed significant differences between the groups. Women who followed a limited “eating window” had improved spatial planning and problem-solving abilities. Additionally, there was a trend towards fewer errors in memory and learning tests, indicating that the participants were better at retaining information and making fewer mistakes related to attention and data recall. However, there were no significant differences in the tests for multitasking and reaction speed between the groups.

According to Sue Shapses, Ph.D., a registered dietitian and the main researcher of the project, the results show that in addition to the benefits of weight loss, it is a change in diet that can provide an additional advantage. The more the meal window is shortened, the more pronounced the cognitive improvements are.

The authors emphasize that this is a pilot study with a relatively small sample, so more extensive work is needed to confirm the findings. In the future, the scientists plan to study the biological mechanisms that may underlie the observed effect. In particular, the relationships between circadian rhythms, nutrient pathways, inflammation levels, and metabolic health are of particular interest.

Thus, the study demonstrates that a simple dietary modification, such as reducing the amount of time spent eating, could potentially be an accessible way to support cognitive function in older adults. It is important to note that the positive effect was observed even when both groups experienced similar weight loss, suggesting that this dietary regimen may have independent neurocognitive benefits.