- A small trial found older women who ate within an eight- to nine-hour window improved more on some planning and problem-solving tests.
- Both the time-restricted group and standard diet group lost similar amounts of weight, suggesting meal timing may have its own effect.
- The findings are preliminary and should not be treated as proof that time-restricted eating protects against dementia.
Time-restricted eating is usually discussed in relation to weight loss and blood sugar.
A small pilot trial suggests it may also affect some aspects of thinking in later life.
The study followed 47 women aged 50 to 79 who had overweight or obesity and were taking part in a six-month weight loss programme.
Everyone was advised to reduce calorie intake by 500 calories a day.
One group was also asked to eat all food within a daily window of less than nine hours.
Most women in that group ate between about 10am and 6pm.
The comparison group ate across a more typical 12-hour window.
After six months, both groups had lost around 15lb on average.
Weight loss was similar, but cognitive results differed.
Women in the time-restricted eating group performed better on tests of spatial planning and problem solving.
They also tended to make fewer memory and learning errors, although that part did not reach statistical significance.
There were no clear differences in reaction time or multitasking.
The result is interesting because it suggests timing may matter, not only calories.
The possible mechanisms are still uncertain.
Meal timing may influence circadian rhythm, inflammation, insulin sensitivity and nutrient-sensing pathways.
All of those can affect brain health, especially as people age.
For a diabetes audience, the caveat is important.
Eating within a shorter window can affect blood glucose patterns and medication timing.
People taking insulin or sulfonylureas should not start fasting or time-restricted eating without clinical advice, because of the risk of hypoglycaemia.
The study was also small and focused only on older women with overweight or obesity.
It was presented at a conference and should be treated as preliminary.
Still, the idea is worth watching.
When we eat may turn out to matter alongside what we eat and how much.
But for now, time-restricted eating should be seen as a possible tool, not a guaranteed brain-health strategy.
