September 6, 2013
Sleep Deprivation Causes People To Buy More Food The Following Day
[ Watch the Video: Junk Food Cravings Can Result From Lack Of Sleep ]
redOrbit Staff & Wire Reports - Your Universe OnlineA lack of slumber has once again been linked to poor food-related choices, as new research in the journal Obesity reports links sleep deprivation with an increase in the amount of food purchased the following day.
Previously associated with an increased desire for junk food by researchers from the University of California-Berkeley (UC-Berkeley) and shown to have an impact on the parts of the brain where food-related choices are made, sleep deprivation has now also been linked to increased levels of a hunger-stimulating hormone.
In the new study, researchers from Sweden explained that they set out to determine whether a lack of proper sleep could impair or alter a person’s food-purchasing choices based on its established tendency to increase hunger and impair higher-level thinking processes.
They discovered that the participants purchased more calories and grams of food the following day while shopping at a mock supermarket, and that the lack of rest increased their blood levels of the hormone ghrelin. There was no direct correlation between individual ghrelin levels and food purchasing habits, they said, suggesting that impulsive decision making or other factors could be responsible for buying more consumables.
“We hypothesized that sleep deprivation's impact on hunger and decision making would make for the 'perfect storm' with regard to shopping and food purchasing – leaving individuals hungrier and less capable of employing self-control and higher-level decision-making processes to avoid making impulsive, calorie-driven purchases,” said first author Colin Chapman of the Uppsala University Department of Neuroscience.
Chapman and his colleagues recruited 14 normal-weight men, and in the morning following both a night of complete sleep deprivation and a night of regular sleep, they presented those men with a fixed budget of approximately $50. Each participant was told to purchase as much as possible out of 40 possible items, 20 of which were high calorie foods and 20 of which were low-calorie foods.
The prices of the high calorie foods were varied to determine if sleep deprivation had an impact on how flexible a person was with their purchasing habits. Furthermore, each subject was given a standardized breakfast in order to limit the effect of hunger on their decision-making during the mock-shopping experience.
According to the study authors, the sleep-deprived men purchased nine percent more total calories and 18 percent more grams of food than they did following a night of sleep. Furthermore, Chapman’s team measured the blood levels of ghrelin and found that the concentration levels of the hormone were higher after total sleep deprivation (although, as noted earlier, the increase did not correlate with food purchasing behavior.)
“Our finding provides a strong rationale for suggesting that patients with concerns regarding caloric intake and weight gain maintain a healthy, normal sleep schedule,” Chapman said.
He and his colleagues note that follow-up studies are needed in order to determine whether the sleep deprivation-induced changes in food purchasing behavior also exist when a person is only partially sleep deprived, as well as whether or not a lack of sleep can also lead to impulsive purchasing in other, non-food-related products.