Late-night snacking could raise risk of diabetes, CVD

Eating at night disrupts the body’s natural clock, encourages fat buildup and could increase a person’s risk for cardiovascular disease and diabetes, research published this week in Experimental Physiology states.

Postprandial triglyceride levels waver throughout the day, Ruud M. Buijs, PhD, and colleagues at the National Autonomous University of Mexico wrote, varying between night and day. Using rat models, Buijs and his team explored the underlying mechanisms of these shifts, ultimately finding the body’s circadian clock is to blame for the hazard of late-night snacking.

Disruption of our natural 24-hour body clock has resulted in evidenced metabolic abnormalities, according to the study—an issue that becomes more difficult to remedy as the American work-life balance takes a back seat to late hours at the office and binge-watching television. Changing up this natural routine can result in odd, unhealthy eating patterns and docked sleep.

Buijs and co-authors measured changes in rats’ triglyceride levels during daily active and resting periods, according to the study, finding that when rats were fed at the beginning of their daily sleeping period, their postprandial plasma triglyceride levels spiked more than when the rodents were fed ahead of their active period. When the rats were active, the researchers wrote, their triglyceride levels were less concentrated due to higher fat uptake by skeletal muscles and brown adipose tissue. The same wasn’t true ahead of the animals’ passive phase.

The suprachiasmatic nucleus (SCN), which controls the body’s circadian rhythm, is responsible for the diurnal pattern of energy metabolism, Buijs and colleagues wrote, and is likely the trigger for variations in triglyceride levels during the course of a day. When the researchers removed the SCN from the brains of one study cohort, they found the rats no longer recorded erratic fat levels. Instead, these variations in triglycerides ceased to exist.

“The fact that we can ignore our biological clock is important for survival; we can decide to sleep during the day when we are extremely tired or we run away from danger at night,” Buijs said in a Physiological Society news release. “However, doing this frequently—with shift work, jet lag or staying up late at night—will harm our health in the long-term, especially when we eat at times when we should sleep.”