With all the advice about exercising and moving more to lose weight, it seems contradictory to read advice to sleep more, but a number of studies associate short sleep times with obesity. The Journal of Clinical Sleep Medicine discusses one that was conducted at Texas Tech University Health Sciences Center. It found that “patients who had sleep times less than seven hours had an increased likelihood of having obesity . . . when compared to a reference group of patients sleeping eight to nine hours.” The researchers’ theories to explain this include the simple observations that people who are awake during more hours a day have more hours to eat and people that are tired tend to exercise less. They also mention the “reduced leptin and elevated ghrelin levels” that occur with sleep deprivation.

According to Clete Kushida, MD, PhD, RPSGT, a neurologist and sleep specialist at the Stanford Sleep Disorders Clinic in California, even after one bad night’s sleep the level of the hormone leptin, which controls hunger, decreases. The level of grehlin increases. It is a hormone, produced by fat cells, that causes you to feel like you need more fat calories and increases hunger.

Stuart Quan, MD, from the Division of Sleep Medicine at Harvard Medical School, found that teens who sleep less than 9 hours have increased risk of being overweight five years later.”

“In a 2007 study published in Sleep Medicine Review, researchers from the University of Chicago found that ‘partial sleep loss may increase the risk of obesity and diabetes via multiple pathways.’ After one night of sleep deprivation, the body has an impaired ability to handle a glucose load.” (WebMD)

Sleep specialist Richard Simon, MD, quoted at the National Sleep Foundation website, states that “because the psychological manifestations of fatigue, sleep and hunger are similar, as adults, we sometimes confuse them—we tend to eat when we’re actually sleepy, because we think fatigue is a sign of hunger.”

Eve Van Cauter, PhD, terms sleep deprivation “the royal route to obesity.”

It’s no wonder that it is, given that according to John Medina in Brain Rules, “sleep loss means mind loss. Sleep loss cripples thinking, in just about every way you can measure thinking. Sleep loss hurts attention, executive function, immediate memory, working memory, mood, quantitative skills, logical reasoning ability, general math knowledge.” Eventually it even affects fine and gross motor movements.

So, of course, we are in no shape to make the best food choices, move our bodies very fast, or even to do the math to count calories or remember how much we’ve already eaten!