Who is obese?
Obesity is an abnormal medical condition in which fat accumulation occurs in our body leading to an 
increase in weight. It increases the risk of various lethal diseases therefore it is becoming a worldwide 
problem. Body mass index (BMI) is the measure of body fat based on height and weight. Those having 
BMI > 25 are considered overweight. 
Relationship between Sleep and BMI
The relationship between sleep and BMI is multilayer and complex. But shortness of sleep leads to fat 
accumulation thus increase in BMI. Sleep and BMI are having reciprocal relationships with each other 
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively 
inhibited sensory activity, inhibition of all voluntary muscles, and reduced interaction with surrounding. 
Importance of sleep
Adequate sleep is essential for our body because it is an important modulator of Neuroendocrine 
functions and glucose metabolism. Insomnia and sleep difficulties are the most common problems faced 
by our general population. Recommended sleep for an adult is 8 hours per night. Research shows, on 
average, adults sleep less than the recommended sleep. Alterations in circadian rhythm due to our more 
exposure to light at night can be the cause of sleep loss. when we stay awake till late at night, delayed 
feedings occur, which affects the synchronized peripheral clock very badly and finally leads to obesity.
Role of Sleep in Obesity
Although it is well-established that an imbalance between caloric intake and physical activity leads to 
obesity. But there are many other factors contributing to the increase in body weight. One of the most 
important factor is sleep. As sleep duration is affecting our energy balance and glucose metabolism so 
it can also affect our body weight. Basically, sleep impacts the secretion of leptin and ghrelin hormones. 
Leptin is a hormone that gives the feeling of satiety while ghrelin is a peptide released by the stomach 
that stimulates appetite. Shortness of sleep increases the level of ghrelin and decreases the level of 
leptin leading to increased food intake thus leading to obesity. A sufficient amount of sleep is required 
to control dietary intake and proper metabolism of the body thus, lack of sleep decreases the intake of 
food and slows down metabolism. 
Sleep disorders and obesity
Obesity is a risk factor for diseases like sleep apnea and arthritis, both of these leads to sleep restriction 
thus there is some possible common etiology between short sleep and obesity. Sleep deprivation leads 
to increased levels of LDL and decreased levels of HDL. This leads to high levels of cholesterol and TAGS. 
Not only the quantity of sleep but the quality of sleep also affects body weight. Fragmentation of sleep 
or a decrease in deep sleep without affecting the overall duration of sleep duration increases in craving
for high carbs diet which can be one of the causes of obesity. Studies suggest that minutes of deep sleep 
are inversely related to waist circumference. It is also been observed that during deep sleep body adapts 
it to the state of decreased food intake by increasing peripheral insulin resistance. Neurons in the 
hypothalamus produce orexin which is involved in the regulation of both sleep and wakefulness. Sleep 
Loss also alters the orexin levels thus all these effects collectively lead to increased weight providing a 
link between sleep and obesity. An Italian study has demonstrated that every additional hour of sleep 
has decreased the incidence of obesity by 30%.
The message
Controlling weight and getting adequate sleep in equally essential to lead a healthy lifestyle. One needs 
to pay more attention to healthy eating and adequate sleep in this era