Sufficient sleep is increasingly being recognized as an essential part of preventing chronic diseases such as diabetes and heart disease. A recent trial conducted at Harvard Medical School, provides further evidence of the detrimental effects insufficient sleep has on chronic disease risk. Researchers found short-term sleep deprivation caused decreases in metabolic rate, increases in fasting blood sugar, and changes in hormones that regulate appetite.
In this study, well-rested participants were kept in laboratory residences without access to natural light. Here, researchers allowed them only 6 1/2 hours of sleep every 28 hours. After the 3 weeks of reduced sleep, participants’ resting metabolic rate (the energy needed to function at rest) fell by 8%. Also, after the sleep deprivation periods, their levels of the appetite stimulating hormone ghrelin were higher and their levels of the appetite suppressing hormone leptin were lower. A recent Mayo Clinic study, in which sleep was limited to 6.5 hours, found similar hormonal changes and also observed that with sleep deprivation subjects consumed on average 529 additional calories compared to those who slept 8 hours per night. Thus, when we get inadequate sleep, our body burns fewer calories and craves more food.
The Harvard study also found that after the 3 week period of sleep deprivation, participants had higher fasting and post-meal blood sugar levels. This means that insufficient sleep significantly worsens risk factors for pre-diabetes and diabetes. “The participants’ glucose control went haywire…in some cases it went from a healthy level to a level considered pre-diabetes,” wrote the lead researcher.
What to do: The average working-age American adult gets 6 hours of sleep but the Centers for Disease Control recommends adults need 7-9 hours of sleep each night. Because too little sleep significantly increases your risk for chronic disease, take your sleep seriously. Limit leisure TV and computer time if it cuts into your sleep and prioritize keeping to consistent sleep patterns. Getting regular activity and creating a quiet sleeping environment can help poor sleepers get their shut-eye. If you have risk factors for obstructive sleep apnea such as upper body obesity, snoring, and/or waking feeling out of breath consider being evaluated by a sleep doctor.
Sources: Nutrition Action Health Letter June 2012, CDC sleep guidelines available at: http://www.cdc.gov/features/sleep/, article available at: http://newsroom.heart.org/pr/aha/lack-of-sleep-may-increase-calorie-230068.aspx