How Sleep Deprivation Affects Your Metabolic Health
By Nicole Molumphy
Do you ever get those late-night cravings or feel like your hunger is never satiated? Research shows that consistent short sleep duration (less than 7 hours per night) can influence metabolic health, affect the function of appetite hormones, increase food cravings, and lead to a 38 percent increase in obesity in adults.
Consistent sleep deprivation can lead to altered functioning of the appetite hormones ghrelin and leptin. Ghrelin increases our appetite and is released by cells in the stomach lining. When your stomach is “growling,” that is the ghrelin hormone talking. Conversely, the hormone leptin, made by our fat cells, lowers our appetite. Studies have revealed that sleep deprivation can lead to increased ghrelin and decreased leptin, resulting in an overall experience of constantly being hungry.
“There are so many health conditions associated with poor sleep,” says Rob Oh, MD, family physician at the Veterans Affairs Health Care System in Palo Alto. “With chronic sleep deprivation, your metabolism becomes dysregulated, leading to cravings for processed foods. Also, you’re less likely to exercise, you feel more stressed, and you’re more likely to think poorly. The combination of these factors can lead to metabolic health problems like obesity and type 2 diabetes.”
Sleep Deprivation Increases Stress Hormones
Our cortisol levels are typically lowest near midnight and then increase towards waking hours, ultimately peaking around 9 a.m. Studies demonstrate that reoccurring poor sleep is associated with an altered cortisol secretion pattern.
For example, delaying your bedtime could lead to high cortisol levels in the middle of the day, rather than just in the morning. Sustained high levels of cortisol can lead to an increased amount of insulin in the blood, which promotes the accumulation of belly fat and has the potential to lead to prediabetes, type 2 diabetes, and other metabolic disorders. An increase in cortisol levels during the day may induce prolonged feelings of stress, increased food cravings, and further insomnia—promoting a recurrent, cyclical pattern.
“Inadequate sleep disrupts hormone levels, which dysregulates one’s metabolism and makes individuals hungrier,” says Dr. Oh. ” When we are hungrier, we eat more, which leads to weight gain and potentially metabolic disease.”
If that’s not bad enough, cravings for ultra-processed foods, sugars, and alcohol become more of a tease with sleep deprivation. A possible mechanism for this added hunger is an increased activation of the endocannabinoid system, which is found throughout the body and controls several biological systems, including sleep, mood, and appetite.
Sleep Deprivation and Increased Risk of Diabetes
Research shows that a lack of sleep may also result in insulin resistance, a driving factor in prediabetes and type 2 diabetes. Insulin is a hormone made by the pancreas that regulates blood glucose levels. Insulin resistance occurs when cells in the liver, fat, and muscles do not respond well to insulin, and in turn, glucose is not taken up into the blood.
The exact mechanism behind the causal relationship between insufficient sleep and insulin resistance is still being studied, however, some studies note that increased inflammatory markers, like C-reactive protein and hormone dysregulation, such as cortisol may be involved.
Currently, prediabetes affects one in three adults in the US. While many mechanisms contribute to the development of prediabetes and type 2 diabetes, some of the more prominent ones include impaired cellular insulin sensitivity, modified gut microbiota, and overly-sensitive sympathetic nervous system (fight-or-flight) activation. When the sympathetic nervous system is activated, it signals the liver to release more glucose into the bloodstream, leading to higher blood sugar levels.
What Can We Do About It?
Unfortunately, research finds that “weekend recovery sleep” is not enough to bring your metabolism back into balance after a lack of sufficient sleep throughout the week. Instead, Dr. Oh recommends taking a holistic approach and examining not only your sleep habits but also your nutritional choices and workout routines to support the restoration of metabolic health.
For those with pre-diabetes and type 2 diabetes, a diet focused on whole foods and low refined carbohydrates is critical for weight loss and glucose control.
Specifically, Dr. Oh recommends a low carbohydrate diet, such as consuming 75 to 100 grams of carbohydrates per day, to control and balance blood sugar levels. He also recommends quick, 20-minute, high intensity workouts for time-efficient and effective exercises that promote metabolic health. Regarding supplements, Dr. Oh recommends magnesium to promote muscle recovery and relaxation before bedtime.
“Optimal sleep is so intertwined with athletic and exercise performance, brain health, and metabolic health,” says Dr. Oh. “Sleep really is a keystone area where many of us can do better and hence reducing our risk for metabolic diseases and lengthening our healthspan.”
