Late-night snacking explained

A researcher at Oregon Health & Science University has an explanation for why people get the urge to snack in the evenings: the body’s internal clock.

In a study published in the journal “Obesity” four that the body’s internal clock (the circadian system) increases hunger and cravings for sweet, starchy and salty foods in the evenings, according to a news release from OHSU.

While the urge to consume more in the evening may have helped our ancestors store energy to survive longer in times of food scarcity, in the current environment of high-calorie food, those late night snacks may result in significant weight gain,” according to the release.

“Of course, there are many factors that affect weight gain, principally diet and exercise, but the time of eating also has an effect. We found with this study that the internal circadian system also likely plays a role in today’s obesity epidemic because it intensifies hunger at night,” said Steven Shea, director for the Center for Research on Occupational and Environmental Toxicology at OHSU and senior author of the study.

“People who eat a lot in the evening, especially high-calorie foods and beverages, are more likely to be overweight or obese,” he added.

Shea and the other researchers involved in the study found study participants felt the least hungry in the morning (8 a.m.) and most hungry in the evening (8 p.m.).

The human body handles nutrients differently depending on the time of day. For example, sugar tolerance is impaired in the evening, according to the news release.

“If weight loss is a goal, it’s probably better to eat your larger, higher-calorie meals earlier in the day,” Shea said in the news release. “Knowing how your body operates will help you make better choices. Going to bed earlier, getting enough sleep and choosing lower-calorie foods rather than higher-calorie foods in the evening can all help with weight loss.”

Marissa Harshman

Marissa Harshman

I'm the health reporter for The Columbian newspaper in Vancouver, Wash. I started at The Columbian -- my hometown newspaper -- in September 2009. Reach me at or 360-735-4546.

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