How does lack of sleep lead to obesity? Scientific analysis and weight loss advice.

Poor sleep can lead to weight gain.

Sleep is crucial for weight loss. A US study investigating the relationship between sleep patterns and body mass index (BMI) of over 1.1 million people showed that women who didn't get enough sleep were 73% more likely to be obese than women who got enough sleep, while women who got enough sleep were generally slimmer.

Sleep deprivation directly leads to increased appetite. Firstly, this is related to ghrelin and leptin, two hormones related to appetite. When sleep is insufficient, ghrelin levels increase significantly, while leptin levels decrease significantly. Furthermore, sleep deprivation leads to elevated cortisol levels, further stimulating the desire to eat, especially cravings for sugary foods.

Secondly, the frontal lobe of the brain is responsible for decision-making and regulating self-control. If sleep is lacking, frontal lobe activity decreases, making people sluggish and less self-controlled. Combined with the increased appetite stimulated by sleep deprivation, people are more likely to crave junk food. Experiments have found that people who don't get enough sleep consume 22% more calories per day than those who get enough sleep. This explains why people who eat the same food often experience poor weight loss results despite staying up late.

Furthermore, many studies have found that sleep deprivation increases insulin levels. This is because lack of sleep significantly reduces insulin sensitivity, prompting the body to secrete more insulin. Insulin, as we know, is a fattening hormone. The higher the insulin level, the greater the likelihood of weight gain.

Meanwhile, basal metabolic rate is also affected by sleep. Many people believe that staying up late increases calorie expenditure. In reality, while staying up late may increase some calorie expenditure that night, the body compensates the next day by lowering the basal metabolic rate to reduce calorie consumption. Moreover, for those trying to lose weight, lack of sleep leads to muscle loss, and muscle is crucial for maintaining basal metabolic rate; muscle loss lowers the basal metabolic rate.

Therefore, getting enough sleep is the most cost-effective way to lose weight.