Issue link: https://cp.revolio.com/i/270856
Abby's Magazine - March / April 2014 | Page 17 offset any extra calories that they burned while staying awake. The research showed that when the subjects were bleary-eyed and sleep-deprived, they strongly preferred the food choices that were highest in calories, like desserts, chocolate and potato chips. The sleepier they felt, the more they wanted the calorie-rich foods. In fact, the foods they requested when they were sleep deprived added up to about 600 calories more than the foods that they wanted when they were well rested. At the same time, brain scans showed that on the morning after the subjects' sleepless night, the heavily caloric foods produced intense activity in an almond-shaped structure called the amygdala, which helps regulate basic emotions as well as our desires for things like food and experiences. That was accompanied by sharply reduced responses in cortical areas of the frontal lobe that regulate decision-making, providing top down control of the amygdala and other primitive brain structures. One expert who was not involved in the new study, Dr. Kenneth P. Wright Jr., called the findings exciting and said that they help explain why people make poor dietary choices and eat much more than they need to when fatigued. "There's something that changes in our brain when we're sleepy that's irrespective of how much energy we need," said Dr. Wright, the director of the sleep and chronobiology lab at the University of Colorado at Boulder. "The brain wants more even when the energy need has been fulfilled." But why would a lack of sleep disrupt the brain response to food? Dr. Walker said he suspected that one factor that plays a role is a substance called adenosine, a metabolic byproduct that disrupts neural function and promotes sleepiness as it accumulates in the brain. One of the ways that caffeine stimulates wakefulness is by blocking adenosine. Adenosine is also cleared from the system when we sleep. Without enough rest, adenosine builds up and may start to degrade communication between networks in the brain, Dr. Walker said. Getting sleep may be the equivalent of rebooting the brain. "I think you have about 16 hours of optimal functioning before the brain needs to go offline and sleep," he said. "If you go beyond these 16 hours into the realm of sleep deprivation, then those brain networks start to break down and become dysfunctional." Dr. Walker said it was increasingly clear from the medical literature that there is not a single tissue in the body that is not beneficially affected by sleep. "It's the single most effective thing people can do every day to reset their brain and body health," he said.