It is a known fact that adequate sleep has multiple health benefits & sleep deprivation is linked with several health complications . Obesity is a major public health concern & it has been observed that it coincides with a pattern of sleeping less. Substantial evidence suggests that sleeping less than 7 hours per night on a regular basis is associated with adverse health consequences especially obesity.
Several studies have been conducted so far to understand the relation between loss of sleep & obesity. A recent meta-analysis (Tasali et al,.2022) suggested that healthy individuals did consume an average of 253 calories more in a single meal during the short-term sleep restriction of up to 14 days. Here, the study focused on observing the effect of sleep extension rather than sleep restriction.
Let us discuss a couple of possible mechanisms that may explain sleep restriction leading to obesity.
Firstly, Chronic partial sleep deprivation leads to feeling of fatigue which may lead to reduction in physical activity. Cross-sectional studies in children have found short sleep durations to be associated with increased television viewing and reduced participation in organized sports. This decreased energy expenditure contributes heavily towards obesity.
Secondly, sleep deprivation may impact the levels of Ghrelin & leptin in the body which are the peripheral regulators of hunger. Short sleepers have reduced levels of leptin (satiety hormone) and elevated levels of ghrelin (hunger hormone) thus causing increased hunger levels. A study restricting sleep for six consecutive days found a similar reduction in leptin that persisted through-out the 24 h day. Also, if most of wake-time is spent in sedentary activities such as watching television etc., curtailed sleep may simply represent an increased opportunity to snack on.
Thirdly, few studies showed that acute sleep deprivation in humans causes a drop-in core body temperature, suggesting that sleep loss may impact energy expenditure through thermoregulation.
There could still be a possibility of other confounding factors like medical disorders involving chronic pain syndromes, as well as psychiatric disorders such as depression. These Conditions are often associated with both short sleep durations and obesity, and might therefore bias measures of the effect of sleep duration on weight. Such conditions may also limit an individual’s ability to be physically active, as well as interfere with sleep continuity. In addition, many medications adversely affect both weight and sleep duration.
Although the mechanisms are unclear, sleep extension in adults who are overweight and have habitual inadequate sleep reduces energy intake and results in weight loss, at least in the short term. Compared with 7-h sleep duration per day, the risk of obesity increases 9% for each 1-h decrease in sleep duration. Thus, along with calorie restriction and regular exercise, sleep hygiene might be an important part of weight management plans for adults.
References
- Gibson-Moore, H. and Chambers, L. (2019) ‘Sleep matters: Can a good night’s sleep help tackle the obesity crisis?’, Nutrition Bulletin, 44(2), pp. 123–129. doi: 10.1111/NBU.12386.
- Paul S. Mueller, M. M. F. (2022) ‘Sleep Extension in Adults Who Are Overweight with Habitual Inadequate Sleep’, NEJM Journal Watch, 2022. doi: 10.1056/NEJM-JW.NA54596.
- Patel, S. R. and Hu, F. B. (2008) ‘Short sleep duration and weight gain: A systematic review’, Obesity, 16(3), pp. 643–653. doi: 10.1038/OBY.2007.118.
- Shaw PJ. Thermoregulatory changes. In: Kushida CA (ed). Sleep Deprivation: Basic Science, Physiology, and Behavior. Marcel Dekker: New York, 2005, pp 319–338
- Zhou, Q., Zhang, M. and Hu, D., 2019. Dose-response association between sleep duration and obesity risk: a systematic review and meta-analysis of prospective cohort studies. Sleep and Breathing, 23 (4), pp.1035-1045.
