One of the most comprehensive studies of the potential link between reduced sleep and childhood obesity finds compelling evidence that children who consistently received less than the recommended hours of sleep during infancy and early childhood had increases in both obesity and in adiposity or overall body fat at age 7.
The study from MassGeneral Hospital for Children (MGHfC) investigators, published in the June issue of Pediatrics, also finds no evidence of a specific period during which insufficient sleep has greater influence on later obesity.
"Our study found convincing evidence that getting less than recommended amounts of sleep across early childhood is an independent and strong risk factor for obesity and adiposity," says Elsie Taveras, MD, MPH, chief of General Pediatrics at MGHfC and lead author of the Pediatrics paper. "Contrary to some published studies, we did not find a particular 'critical period' for the influence of sleep duration on weight gain. Instead, insufficient sleep at any time in early childhood had adverse effects."
While several studies have found evidence of an association between sleep and obesity in young children, few have examined the effects of constant sleep deprivation across time or used measures other than body mass index (BMI), which determines obesity based solely on height and weight. The current study analyzed data from Project Viva, a long-term investigation of the health impacts of several factors during pregnancy and after birth. Information used in this study was gathered from mothers at in-person interviews when their children were around 6 months, 3 years and 7 years old, and from questionnaires completed when the children were ages 1, 2, 4, 5 and 6.
Among other questions, the mothers were asked how much time their children slept, both at night and during daytime naps, during an average day. Measurements taken at the seven-year visit included not only height and weight but also total body fat, abdominal fat, lean body mass, and waist and hip circumferences – measurements that may more accurately reflect cardio-metabolic health risks than BMI alone. Curtailed sleep was defined as less than 12 hours per day from ages 6 months to 2 years, less than 10 hours per day for ages 3 and 4, and less than 9 hours per day from age 5 to 7. Based on the mothers' reports at each age, individual children were assigned a sleep score covering the entire study period – from 0, which represented the highest level of sleep curtailment, to 13, indicating no reports of insufficient sleep.
Overall, children with the lowest sleep scores had the highest levels of all body measurements reflecting obesity and adiposity, including abdominal fat which is considered to be particularly hazardous. The association was consistent at all ages, indicting there was no critical period for the interaction between sleep and weight. Lower sleep scores were more common in homes with lower incomes, less maternal education and among racial and ethnic minorities; but the association between sleep and obesity/adiposity was not changed by adjusting for those and other factors.
While more research is needed to understand how sleep duration affects body composition, Taveras notes, potential mechanisms could include the influence of sleep on hormones that control hunger and satiety; the disruptions of circadian rhythms or possible common genetic pathways involved in both sleep and metabolism; poor ability to make good decisions on food choices and eating behaviors caused by sleep deprivation, or household routines that lead to both reduced sleep and increased food consumption. Insufficient sleep may also lead to increased opportunities to eat, especially if time is spent in sedentary activities, such as TV viewing, when snacking and exposure to ads for unhealthy foods are common.
"While we need more trials to determine if improving sleep leads to reduced obesity," she says, "right now we can recommend that clinicians teach young patients and their parents ways to get a better night's sleep – including setting a consistent bedtime, limiting caffeinated beverages late in the day and cutting out high-tech distractions in the bedroom. All of these help promote good sleep habits, which also may boost alertness for school or work, improve mood and enhance the overall quality of life." Taveras is an associate professor of Pediatrics and Population Medicine at Harvard Medical School (HMS).
Additional co-authors of the Pediatrics report are Michelle-Maria Peña, MGHfC Division of General Pediatrics; Matthew Gillman, MD, SM, and Sheryl Rifas-Shiman, MPH, HMS Department of Population Medicine; and Susan Redline, MD, MPH, Brigham and Women's Hospital. The study was supported by National Cancer Institute grant U54CA116847 and Eunice Kennedy Shriver National Institute of Child Health and Human Development grant R37HD034568.
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $785 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine.
Kory Dodd Zhao |
Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
27.06.2017 | Power and Electrical Engineering
27.06.2017 | Information Technology
27.06.2017 | Physics and Astronomy