Not getting enough rest has a negative impact on your health and physical wellbeing. One outcome of sleep deprivation may be an uptick in the number of calories you consume. Poor diet quality and excessive body weight may also stem from lack of sleep.
The relationship between lack of sleep and eating excessively is likely tied to hormonal functions in the body. Getting a good night’s rest promotes a healthy balance of hormones, including those that regulate appetite, digestion, and metabolism.
A good night’s rest promotes healthy production of hormones that control appetite, including leptin and ghrelin. Leptin is a peptide hormone that regulates your body’s energy balance by hindering feelings of hunger and regulating fat storage. Gherin — a hormone secreted in the stomach that acts as a counterpart to leptin — boosts appetite, growth, and fat production.
Sufficient, restful sleep allows the body to regulate production of these two hormones, creating a balance of appetite and satiation. Likewise, lack of sleep can create an imbalance in the body that increases ghrelin levels and lowers leptin levels. This can cause you to feel hungrier during the day. This imbalance caused by sleep deprivation may lead to a higher calorie intake during the day.
Additionally, sleep loss can impact how your body reacts to production of insulin, the hormone that regulates blood sugar levels. This can in turn put you at higher risk for diabetes, a disease that alters the way your body converts food into energy. Obesity is considered a major predictor for diabetes.
One recent study found that partial sleep deprivation did not significantly affect energy expenditure or resting metabolic rate, or the amount of calories burned when your body is at rest. However, researchers noted that sleep-deprived people tend to consume less fat and protein while their carbohydrate intake remains stagnant.
Although epidemiological studies point to a link between lack of sleep and obesity, as well as a link between short sleep duration and a high body mass index (BMI), researchers have yet to establish how much sleep deprivation impacts appetite and food desire.
In addition to inhibiting healthy production of leptin and ghrelin, lack of sleep can also lead to feelings of fatigue. People who experience fatigue — particularly older adults — are less likely to engage in physical activity. Fatigue may also affect BMI.
While sleep duration has been shown to affect appetite and caloric intake, sleep quality is also crucial. Those who sleep poorly, especially women, are more likely to follow a less healthy diet. This puts them at higher risk of cardiovascular disease and obesity.
Sleep loss has not conclusively been shown to cause lack of appetite. That said, some medical conditions are often characterized by both fatigue and appetite loss. For example, different types of cancer — as well as certain cancer treatment methods — can cause weight loss when the body does not receive enough nutrients and fatigue brought on by muscle loss.
Other conditions that can cause fatigue and loss of appetite include influenza, food poisoning, hay fever and other allergies, fibromyalgia, and Crohn’s disease. Some women also experience fatigue and appetite loss during their pre-menstrual cycle, though conversely, some will increase their intake of certain foods.
If you’re concurrently experiencing fatigue and loss of appetite, there may be an underlying medical condition causing these symptoms. Talk to your doctor about treatment options, and don’t assume you’re eating less simply because you feel tired.