Obesity is a main public health problem. Over the past several decades, obesity rates have risen to the degree that one billion adults are currently overweight, and one-third of US adults meet the criteria for obesity. More recently, there has been heightened interest in the role of sleep in weight control and obesity. Sleep is a restorative process of the brain, by the brain, and for the brain, but it is now clear that sleep is essential for the entire body’s health. The decrease in sleep duration and increase in sleep complaints in modern society raises concerns for the negative impact of chronic sleep disturbances on health in general, not only mental health.
Behavioral sleep curtailment is becoming endemic in modern times. Ours is a 24-h society with more evening and night-time work and leisure activities, which all lead to a sacrifice of hours available for sleep. This has had a significant impact on sleep time, duration of dark exposure, and overall organization of circadian rhythms through the exposure to artificial light after sunset and often before sunrise, resulting in later bedtimes, reduced total sleep time, and the opportunity to be active and ingest food during the natural night.
Approximately most epidemiological studies done in different geographical regions have investigated the association between sleep and obesity in adults and children. The majority found a significant association between short sleep (generally <6 h per night) and increased obesity risk.
A study recommended that individuals consumed more snacks as well as snacks with higher carbohydrate content (particularly between 7 PM and 7 AM) when subjected to restricted sleep (5.5 h) vs. normal sleep (8.5 h) duration for 3-week periods. These results support the hypothesis that reduced sleep duration may provide increased time available for snacking and greater carbohydrate consumption, thereby increasing total energy intake and subsequently impairing weight loss.
A study among Chinese adults also found a significant association between sleep duration and greater energy consumption. However, the excess intake was contributed by dietary fat in this population. Specifically, adults sleeping <7 h/night had a significantly higher energy intake from fat than those sleeping 7–9 h/night.
The results of most studies suggest that overweight/obese people who enter a weight-loss program would have a higher chance of continued weight-loss success if sleep quality is high and/or sleep duration averages >7 h/night at the time of study enrollment.
These findings may be necessary for the overall approach to obesity management among overweight/obese people in that sleep may be a modifiable component of weight-loss therapy.
The recommended sleep duration advised by the National Sleep Foundation is between 7 and 9 h/night, based on epidemiological evidence indicating that individuals who sleep <6 or >9 h/night have higher mortality rates than those who sleep 7–8 h/night.
- The worldwide increase in the prevalence of obesity in the last several decades has been paralleled by a trend of reduced sleep duration in adults and children.
- Studies suggest that sleep restriction leads to hormonal alterations, which may favor increased calorie intake and a decreased energy expenditure and ultimately lead to weight gain.
- In addition to short sleep duration, evidence suggests that sleep disturbance, such as obstructive sleep apnea and poor sleep quality, may increase obesity risk.
- If your weight loss efforts are not producing results, it may be time to examine your sleep habits.