Researchers from the University of Surrey discovered that delaying meal times delays the circadian rhythm of sugar in the blood. The findings could prove to be a breakthrough in alleviating symptoms of jet lag and shift work, a study in the journal Current Biology reports.
Jonathan Johnston, PhD, and Sophie Wehrens, PhD, from the University of Surrey examined the impact of altering meal times on the circadian rhythms of 10 volunteers.
Volunteers were provided with three meals breakfast, lunch, and dinner. In the first phase of the study, the first meal was provided 30 minutes after waking, with later meals at subsequent five hour intervals whilst in the second phase each meal was delayed by five hours after waking. Immediately after each phase, sequential blood samples and fat biopsies were taken from each volunteer in specialized laboratory conditions that allow measurement of internal circadian rhythms.
Researchers discovered that postponing meal times by five hours delayed rhythms of blood sugar by the same time frame. This discovery demonstrates that mealtimes synchronize internal clocks that control rhythms of blood sugar concentration. Researchers indicated that people who struggle with circadian rhythm disorders, including shift workers and long haul flights, might consider timed meals to help resynchronize their body clocks.
“A 5-hour delay in meal times causes a 5-hour delay in our internal blood sugar rhythms,” says Johnston in a release. “We think this is due to changes in clocks in our metabolic tissues, but not the ‘master’ clock in the brain.
“We anticipated seeing some delays in rhythms after the late meals, but the size of the change in blood sugar rhythms was surprising. It was also surprising that other metabolic rhythms, including blood insulin and triglyceride, did not change.”
Surprisingly researchers uncovered that the delay in meal times did not affect insulin or triglyceride (fat) levels in the blood indicating that blood glucose rhythms can be governed by separate circadian clocks to these other key aspects of rhythmic metabolism.
Johnston says, “It has been shown that regular jet lag and shift work have adverse effects on the body, including metabolic disturbances. Altering meal times can reset the body clocks regulating sugar metabolism in a drug-free way. This will help us design feeding regimes to reduce the risk of developing health problems such as obesity and cardiovascular disease in people with disturbed circadian rhythms.”