The human body operates on a 24-hour cycle we call the “circadian rhythm.” This cycle, which drives key functions like sleep and digestion, is heavily influenced by light exposure and mealtimes.
Disrupting this cycle – such as eating at odd times or eating when your brain wants to sleep – can be detrimental to your health.
“Because we eat during the day, insulin should be produced during the day and glucose at night” explains Noga Kronfeld-Schor, a Zoology Professor in Tel Aviv. “Everything has to be done at the right time. If you disrupt or de-synch the clock by working night shifts or eating at night it disrupts that homeostasis.”
In a recent study published in the journal Obesity, authors explain how “time-restricted feeding” can improve glucose tolerance in men at risk for Type 2 diabetes.
During the study, 15 participants were allowed to eat whatever they wanted, but only within a 9-hour timeframe. Group 1 ate between the hours of 8am and 5pm and Group 2 ate between 12pm and 9pm.
In effect, the restricted feeding schedule “reset” patients’ circadian rhythms so that their minds and bodies were in sync.
Groups 1 and 2 demonstrated equal improvements in health and in glucose control. Some patients experienced weight loss despite no change in energy intake.
The results support previous findings about the timing of meals and weight loss.
“If you usually eat for 15 hours a day and come down to 12, you’ll see an improvement,” explains lead study author Leonie Heilbronn.
A second study, published April 2019 in the journal Cell, suggests the hormone insulin is a driving signal for the circadian rhythm.
Insulin is also the key player in diabetes.
“Our data suggests that eating at the wrong times could have a major impact on our circadian rhythms,” writes study author Priya Crosby.
“There is still work to do here, but paying particular attention to meal timing and light exposure is likely the best way to mitigate the adverse effects of shift-work. Even for those who work traditional hours, being careful about when we eat is an important way to help maintain healthy body clocks, especially as we age.”