Research by scientists from King's College, London, reveals that people who sleep longer hours are less likely to snack on carbs and sugary foods. It is already known that not getting enough sleep can contribute to obesity by changing the hormone levels responsible for controlling appetite, but this new study, published in the American Journal of Clinical Nutrition, shows that by sleeping longer, people automatically select healthier food options within just one short week, eating an average of 10 grams less of sugar daily.
"The fact that extending sleep led to a reduction in intake of free sugars — by which we mean the sugars that are added to foods by manufacturers or in cooking at home as well as sugars in honey, syrups and fruit juice — suggests that a simple change in lifestyle may really help people to consume healthier diets," said Dr. Wendy Hall, the principal investigator of the study.
During the study, 21 volunteers who usually sleep less than seven hours per night were asked to attend counseling sessions to learn techniques to sleep longer hours. They were asked to maintain a fixed bedtime, avoid caffeine and food before bed and spend their evening engaging in a relaxing activity. On average, the study participants were able to get 90 more minutes of sleep during the seven day trial period.
The volunteers also kept food diaries recording what they ate throughout the trial. By the end of the week, the participants were eating less sugar and carbs than at the beginning of the trial. No changes were seen in the control group that maintained their normal sleeping hours.
"Sleep duration and quality is an area of increasing public health concern and has been linked as a risk factor for various conditions. We have shown that sleep habits can be changed with relative ease in healthy adults using a personalised approach," researcher Haya Al-Khatib said.
Increasing time in bed for just an hour or so could impact the food choices we make, Khatib also notes.
"We hope to investigate this finding further with longer-term studies examining nutrient intake and continued adherence to sleep extension behaviours in more detail, especially in populations at risk of obesity or cardiovascular disease."