How the Tired Brain Directs Junk-Food Binges

Air Date:
Heard On The Larry Meiller Show

We know that lack of sleep isn’t good for our health, and so is eating food that is bad for us. Larry Meiller finds out what the link is between sleep disorders and binging on junk food.

Featured in this Show

  • Sleep Deprivation Sets Us Up To Overeat

    You haven’t been sleeping well all week, and when mid-afternoon hits, all you can think of is a big frosted brownie or maybe a coffee drink loaded with flavorings, milk, and even some whipped cream on top. Does this sound familiar? We know that lack of sleep isn’t good for our health, and neither is eating food that is bad for us. You may not connect the two, but two UW-Madison researchers have found that there can indeed be a cause and effect at work.

    Eating is a matter of survival since our bodies need a certain amount of calories to have the energy to live, but that’s not the only thing driving our eating. Brian Baldo is an assistant professor of psychiatry at the University of Wisconsin-Madison. He specializes in the neural basis of eating disorders and addiction.

    Baldo knows that we eat for many different reasons. “Anyone who’s had a full, nutritionally complete meal and then afterwards had a big piece of chocolate cake, knows that there’s another side to it,” Baldo says. There is also the pleasure that we get from eating certain kinds of foods. His research looks at the systems in the brain that control eating, but he is especially interested in why we go for that chocolate cake.

    Two chemical systems play important roles in that desire and fulfillment. The dopamine system is closely linked to what we experience as pleasurable or rewarding experiences. But even more important to understand why we overeat is to understand the role that opiates play. These are the same receptors in our brain that are stimulated when using heroin or other drugs, including pain medications like morphine. Baldo explains that “these brain chemicals greatly magnify or enhance the rewarding aspects of eating yummy foods like tasty snacks, salty chips, sweet-tasting, high-fat foods, and so on.”

    So chemically, it’s no wonder we’re tempted to reach for pleasing foods that aren’t necessary for our survival. And when we look at humans’ evolutionary development, Baldo says that attraction to very high calorie foods would have made sense. “When food was scarce and hard to get, it was probably advantageous that we were drawn to foods that were very energy-dense. And if we found them very rewarding, that would be a very efficient way to get us to eat more and more. To help us survive in case we couldn’t find it the next time around.”

    Of course today, high calorie foods with a lot of fat and sugar in them are very easy to come by, and few of us are in any danger of not getting enough calories on a daily basis to survive. But those brain chemicals make it difficult for us to eat only what we need and what is healthy.

    In addition, sleep deprivation can also play a role in overeating, and in consuming those calorie dense foods. Dr. Ruth Benca is a professor of Psychology and Psychiatry at the University of Wisconsin-Madison. She also directs the Wisconsin Sleep laboratory and clinic.

    One of the first reactions to sleep deprivation is to eat more. And it isn’t carrots and lean protein that we tend to reach for. “We start going after the junk food: the ice cream, the cookies, the candy,” Benca says. “Late at night, we’re all looking for something sweet,” even if we’ve had more than enough to eat for our physical needs.

    That correlation is particularly worrisome since, as Benca explains, our society is becoming more and more sleep deprived. In fact, over the last half a century, the trend has been for people to get at least 20 percent less sleep than before. Obesity has increased significantly over the same time period.

    Benca shares that well-controlled studies have been done that show that when people’s sleep is restricted to five hours a night, those subjects will go for those high-reward foods that Baldo discussed. They will also gravitate towards them close to bedtime, when sleep deprivation is at its height. The result is weight gain.

    It may be that sleep deprivation reduces normal regulation of those chemical systems in the brain that control what we eat. They found that “the ‘food-liking switch’ gets stuck in the on position, and no matter how much you eat, you still are going to try and eat more, even though you way overshot your calorie needs for the day” Benca explains.

    Conversely, for people who are actively dieting, Benca says that a lack of sleep can sabotage their efforts. The dieter may still lose weight, but Benca warns that instead of losing mostly body fat, lack of sleep will cause your body to also shed lean body tissue or muscle as well.

    So while skimping on sleep may be tempting in order to get more done during waking hours, it could backfire in significant ways. If you are living with a sleep disorder that makes getting enough sleep impossible, it’s worth prioritizing getting it treated. Otherwise, it’s likely that your waistline will expand and your health will be impacted.

Episode Credits

  • Larry Meiller Host
  • Brian A Baldo Guest
  • Ruth Benca Guest

Related Stories