Clinical ReviewLongitudinal associations between sleep duration and subsequent weight gain: A systematic review
Introduction
According to the Centers for Disease Control and Prevention (CDC) more than one-third of adults and 17% of children in the United States (U.S.) are obese; in the past three decades, obesity rates for adults doubled while rates for children tripled.1 To stem this epidemic, the CDC recommends regular physical activity and healthy nutritional practices. A growing body of evidence points to another important risk factor for both weight gain and obesity: getting too little sleep.*2, 3
Previous literature reviews and meta-analyses have reported significant associations between sleep duration and obesity.*2, 3, *4, 5, 6, 7, 8, 9 These reviews indicate that there is evidence that sleep duration is associated with being overweight and/or experiencing weight gain over time. The majority of review conclusions support Nielsen et al.7 who state that “short sleep duration is consistently associated with development of obesity in children and young adults, but not consistently so in older adults”.
There are multiple mechanisms through which sleep deprivation is hypothesized to have a causal link with weight gain. First, there is experimental evidence at the physiologic level. Evidence indicates short sleep may result in hormonal and metabolic changes contributing to weight gain and obesity.10, 11, 12, 13 For example, studies of young healthy men found sleep curtailment was associated with increased ghrelin levels and decreased leptin levels, corresponding to increased hunger and appetite.11, 14 Suppressed leptin levels10, 12, 14 and elevated ghrelin levels10, 14 related to short sleep duration have been confirmed by other studies. Also, an association between sleep deprivation and thermoregulation decreases the available energy expenditure and is related to increased food intake.15 In addition, short sleep duration has been associated with fatigue and reduced physical activity, a source of reduced caloric expenditure.16 And finally, being awake longer gives one more opportunity to eat, coupled with the fact that sleep deprivation may affect choices about food quality. While there is evidence that meal intake remains stable among sleep durations, sleep restriction is associated with an increased consumption of calories from snacks prior to bedtime17 and an average daily increase in calories consumed from fat.18
Media use (e.g., television, video games, computers) has grown dramatically in the U.S., which has also been associated with short sleep and obesity. With 24-h media availability, the amount of time spent with entertainment media has risen, especially among youth.19, 20 In 2009 U.S. children aged 8-18 spent 7 h and 38 min per day using entertainment media.21 Of those aged 8–18, 71% have a television in their bedroom, 50% have a game console in their bedroom,20 33% have internet access in their bedroom, which makes parental monitoring difficult and may have direct effects on nighttime sleep schedules.20, 21
Short sleep duration is a known risk factor for overweight22 and obesity,23 and media use is associated with both short sleep and obesity in infants, children, and adolescents around the world.*22, 23, 24, 25, 26, 27, 28 Taveras et al.22 report that a combination of short sleep duration and high levels of television in infants predict a 17% probability of overweight in 3 years, more than twice the predicted probability of having either short sleep duration or high levels of television alone. Infant television and video viewing is associated with shorter sleep duration at age 1 and 2 years.25 Ortega et al.26 found that insufficient sleep and ≥3 h/day television watching were significantly associated among adolescents in Spain. Vioque et al.23 found that people aged 15 years and older in Spain who watched television ≥4 h a day were significantly more likely to be obese compared to those who watched ≤1 h per day. Gortmaker et al.27 observed a strong dose-response relationship between the prevalence of overweight and the hours of television viewed. A randomized controlled trial found that relative to controls, an intervention group receiving instruction on reducing television, videotape and video game use had statistically significant decreases in children’s reported television viewing and statistically significant relative decreases in BMI, concluding that reducing media use may be a promising approach towards preventing childhood obesity.28
As with the relationship between sleep duration and all-cause mortality,29, 30 some studies of adults have found that both short and long sleeping are associated with weight gain. Regarding the u-shaped curves, the proposed mechanisms behind an association between long sleep duration and weight gain are at least partially distinct from those of short sleep.9For example, weight gain among the longer sleepers may be related to less physical activity among the long sleepers or other third factors such as co-morbidities.
Section snippets
Challenges in interpreting the results from previous studies on sleep duration and weight gain
There are numerous challenges in comparing the various associations between short sleep and weight gain across studies.2 First, the definition of short sleep measured in hours across studies is far from standard, with “short sleep” measurement varying from “two to 4 h” per night in adults31 to “less than 11 h” per night in five-year old children.32 In addition, the inclusion of confounding variables varies widely among studies.*2, *4, 5, 6 Finally, the majority of studies to date have been
Methods
We performed a systematic literature search in PubMed for relevant original publications meeting the following criteria from 1990 through June 21, 2010 to identify original publications: (“sleep”[MeSH Terms] OR “sleep”[All Fields]) AND ((“obesity"[MeSH Terms] OR “obesity”[All Fields]) OR “weight gain”[All Fields] OR “BMI”[All Fields] OR “overweight”[MeSH Terms] OR “overweight” [All Fields]) NOT (“sleep apnea” OR “apnea” OR “narcolepsy” OR “sleep disorder” OR “sleep disorders” OR “sleep
Results
In total, we reviewed 20 longitudinal studies. While adult studies (n = 13) reported inconsistent results on the association between sleep duration and subsequent weight gain, studies with children (n = 7) consistently reported a negative association between sleep duration and subsequent weight gain.
Table 1 summarizes the identified 13 adult studies. Four found an association between short sleep and weight gain but no association between long sleep and weight gain.16, 40, 41, *42 Four found an
Discussion
This study provides for the first time a systematic review of longitudinal-only studies examining the association between sleep duration and subsequent weight gain.
Children studies in this review consistently reported a relationship between short sleep duration and weight gain with the exception of the older children (8.0–12.9 years at baseline and followed for 5 years) in one study.56 The results of the adult studies were more varied, with four studies finding an association between only short
Acknowledgment
This research is funded in part by grants R21HD060208 and R01AG036868.
References∗ (69)
- et al.
Impact of sleep debt on metabolic and endocrine function
Lancet
(1999) - et al.
Acute partial sleep deprvation increases food intake in healthy men
Am J Clin Nutr
(2010) - et al.
Sleep deprivation in the rat by the disk-over-water method
Behav Brain Res
(1995) - et al.
Sleep curtailment is accompanied by increased intake of calories from snacks
Am J Clin Nutr
(2009) - et al.
Associations of early life risk factors with infant sleep duration
Acad Pediatr
(2010) - et al.
Sleep duration, general and abdominal obesity, and weight change among the older adult population of Spain
Am J Clin Nutr
(2008) - et al.
Risk factors for childhood overweight: a prospective study from birth to 9.5 years
J Pediatr
(2004) - et al.
A link between chronic sleep restriction and obesity: methodological considerations
Public Health
(2008) Halting the epidemic by making health easier: at a glance 2010
(2010)- et al.
Short sleep duration and weight gain: a systematic review
Obesity
(2008)
Sleep and the epidemic of obesity in children and adults
Eur J Endocrinol
Is sleep duration related to obesity? A critical review of the epidemiological evidence
Sleep Med Rev
Is sleep duration associated with childhood obesity? A systematic review and metanalysis
Obesity
Meta-analysis of short sleep duration and obesity in children and adults
Sleep
Short sleep duration as a possible cause of obesity: critical analysis of the epidemiological evidence
Obes Rev
Shortened sleep duration is associated with pediatric overweight
Behav Sleep Med
Associations between sleep loss and increased risk of obesity and diabetes
Ann N Y Acad Sci
Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index
PLos Med
Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite
Ann Intern Med
Short sleep duration is associated with reduced leptin levels and increased adiposity: results from the Quebec family study
Obesity
Association between reduced sleep and weight gain in women
Am J Epidemiol
The association of sleep duration with adolescents’ fat and carbohydrate consumption
Sleep
Televisions in the bedrooms of racial./ethnic minority children: how did they get there and how do we get them out?
Clin Pediatr (Phila)
Generation M2: media lives of 8- to 18-year-olds
Short sleep duration in infancy and risk of childhood overweight
Arch Pediatr Adolesc Med
Time spent watching television, sleep duration and obesity in adults living in Valencia, Spain
Int J Obes (Lond)
Television viewing and sleep are associated with overweight among urban and semi-urban South Indian children
Nutr J
Sleep patterns in Spanish adolescents: associations with watching TV and leisure-time physical activity
Eur J Appl Physiol
Television viewing as a cause of increasing obesity among children in the United States, 1986-1990
Arch Pediatr Adolesc Med
Reducing children’s television viewing to prevent obesity
JAMA
Mortality related to actigraphic long and short sleep
Sleep Med
Self-reported sleep duration as a predictor of all-cause mortality: results from the JACC study, Japan
Sleep
Inadequate sleep as a risk factor for obesity: analyses of the NHANES I
Sleep
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