September 6, 2013
News Review From Harvard Medical School -- Sleepy Shoppers Haul Home More Calories
Groggy grocery buying can make you fat. That's one possible conclusion from a new study. Researchers gave 14 normal-weight men about $50 each to spend on a morning shopping trip. This occurred after they had been sleep deprived the night before. They repeated the shopping excursion on the morning after a normal night's sleep. In each case, the men could choose any of 40 foods to buy. The list was evenly split between high-calorie and low-calorie items. They were supposed to spend most of the money. Before both trips, the men were given a hearty breakfast so they wouldn't be hungry. Men bought 18% more food, with 9% more calories, after being sleep deprived than after having enough sleep. The journal Obesity published the study online. HealthDay News wrote about it September 5.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Most people know it's a bad idea to shop for food when you're hungry. It's a formula for filling your cart with high-calorie foods, and likely spending more money than expected.
Now we learn that food shopping when you're sleep deprived may be just as dangerous. This simple experiment looked at what foods 14 normal-weight men bought on 2 morning shopping trips. One trip followed a single night of sleep deprivation. The other came after a good night's sleep.
For each trip, the men received the equivalent of 50 U.S. dollars to spend. They were told to buy as much as they could out of a possible 40 items. Twenty of the foods were high-calorie and 20 were low-calorie.
To make sure the men weren't hungry, they were fed a solid breakfast before food shopping.
The men bought more grams of food and more high-calorie foods on the morning after sleep deprivation than they did after a more standard night’s sleep.
Not getting enough sleep is linked with gaining weight. This study adds another potential reason. Earlier studies have suggested other possible reasons:
What Changes Can I Make Now?
Be aware of how your body responds when you don't get enough sleep. If possible, schedule your food shopping on a day after you can get at least 7 hours of sleep. Focus on mindful eating even more than usual when you know you are sleep deprived and tired.
Quality of sleep matters just as much as how long you sleep. This can be a real challenge for people who work the night shift or can't get into bed when it's dark outside.
If you are fortunate enough to have a regular sleep schedule, here are some ways to help you get better quality sleep:
If you do have an irregular sleep schedule, try to avoid bright lights for at least an hour before you get into bed. Wear sunglasses if necessary.
If you work the night shift, you will need to adjust this advice based on your schedule. For example, go directly to bed as soon as you get home from work.
What Can I Expect Looking to the Future?
This may be a small study, but it is just the type of research we need. Studies like this can help us understand the behaviors that can lead to weight gain and obesity.
It's interesting that the researchers decided to choose men rather than women. Perhaps in Sweden, where the study was done, men do more of the grocery shopping. We certainly need to see if the results will be the same in women.