When sleep is restricted, ghrelin levels rise and leptin levels fall, leading to increased hunger and calorie consumption, particularly for high-fat and high-sugar foods. (File Image)
Sleep is a fundamental pillar of health, influencing everything from cognitive function to immune response. However, one of the lesser-known but significant consequences of sleep deprivation is its impact on metabolism, body fat accumulation and cholesterol levels. Research increasingly points to a strong connection between inadequate sleep and metabolic disorders, including obesity, dyslipidemia (abnormal cholesterol levels) and fatty liver disease.
Sleep deprivation alters the body’s hormonal balance, leading to weight gain and increased fat accumulation. The two primary hormones affected are ghrelin, which stimulates appetite and leptin, which signals satiety to the brain. When sleep is restricted, ghrelin levels rise and leptin levels fall, leading to increased hunger and calorie consumption, particularly for high-fat and high-sugar foods.
Additionally, chronic sleep deprivation disrupts the body’s insulin sensitivity. Insulin is responsible for regulating blood sugar levels and when cells become resistant to insulin, excess glucose is stored as fat. Studies suggest that sleep deprivation can lead to increased visceral fat — fat stored around internal organs — which is a significant risk factor for metabolic diseases, including fatty liver disease.
Non-alcoholic fatty liver disease (NAFLD) is a condition characterized by excessive fat buildup-in the liver. The liver plays a crucial role in metabolising fats and detoxifying the blood, and disrupted sleep cycles interfere with these functions. Sleep deprivation leads to increased production of free fatty acids and triglycerides, which accumulate in liver cells, causing inflammation and potential liver damage.
Another contributing factor is circadian rhythm disruption. The body’s internal clock regulates metabolic processes, including fat metabolism in the liver. When sleep patterns are irregular—such as in shift workers or individuals with chronic insomnia—the liver’s ability to process fats is compromised, leading to fat accumulation and increasing the risk of liver fibrosis (scarring).
Given the strong connection between sleep deprivation and body fat accumulation, here are some strategies to improve sleep and reduce associated health risks: