From Sleep Deprivation to Obesity

Obesity is one of the biggest and costliest public health crises of the 21st century. According to the World Health Organization, 13 percent of the adult population worldwide was obese in 2016, and almost 40 percent of adults over the age of 18 were severely overweight. These numbers, startling as they are, have only increased over the past few years. In fact, data shows that obesity and overweight rates have been steadily climbing over the past five decades, from 14 percent of Americans having a body mass index (BMI) greater than 30 in 1962, to nearly 40 percent in 2019.

Sleep Deprivation Diagram

Many factors influence a person’s weight. Genetic predispositions and chronic conditions play a big role in someone’s risk of becoming obese or overweight, but lifestyle choices and eating habits are the driving force behind the global obesity epidemic. Lifestyle choices are the behaviors that a person decides to engage in that impact their health in one way or another. For example, exercising, drinking water, and reducing salt and sugar intake are all healthy lifestyle choices. On the other hand, smoking, eating junk food, and drinking too much alcohol are examples of poor lifestyle choices.

One healthy lifestyle choice that we tend to overlook is getting enough sleep. The importance of sleep goes beyond resting when we are tired. Getting a good night’s sleep is essential for a number of functions, ranging from memory formation and consolidation to lowering the risk for heart disease and other chronic conditions. Research also suggests that sleeping well at night helps the body regulate calories more efficiently.

Even though the exact link between sleep and obesity is not fully understood, there is substantial evidence that suggests that people who are sleep deprived have a higher risk of being obese or overweight. Why? One possible explanation is the relationship between sleep and hormones.

When you fall asleep, the body performs thousands of important processes like repairing tissues and secreting cytokines. Cytokines are a cluster of small proteins that help cells communicate and aid with immune functioning. During that time, the body is also flooded with all kinds of hormones, including leptin and ghrelin.

Ghrelin and leptin, known together as the “hunger hormones” are two essential hormones that directly influence your appetite and food intake. Ghrelin is produced by cells in the gastrointestinal tract – aka, the gut – and its main role is to increase appetite. Leptin, on the other hand, is made in the small intestine, and it inhibits hunger and regulates energy balance.

In a research study of 1,024 participants, researchers found that short sleep duration – 7.7 hours or less – not only was associated with a higher BMI; people who slept less also had lower levels of leptin and higher levels of ghrelin. These changes in normal hormonal patterns usually result in more hunger and less satiety, which can lead to obesity and overweight.

Though obesity can be caused by a myriad of factors, the process by which humans gain weight is fairly simple. When you consume more calories than you burn, your body ends up with more energy than it can spend. When this happens, the body stores leftover energy in adipose tissues (fat cells) to be used another time. If you consistently consume more calories than you burn, your body has to keep making new fat cells and enlarging the ones you already had. Conversely, if you decrease your calorie intake or burn more calories than you eat, your body doesn’t need to store as much energy, so fat cells eventually shrink.

Contrary to popular belief, not all calories are burned through exercise. Even when you are resting, the body burns energy by performing vital basic functions like breathing, thinking, and digesting food. Your basal metabolic rate is the number of calories your body needs to perform such tasks. Another one of these functions is thermoregulation, which is the process that allows your body to maintain a normal internal temperature even when it is hot or cold outside. Sleep deprivation disrupts your body’s ability to regulate its internal temperature effectively, potentially slowing down your basal metabolic rate.

The path to obesity is not a straight one. Your family history, the medications that you take, the foods that you eat, and even how long and well you sleep at night can make an impact on both your waistline and your health. Choosing to engage in healthy behaviors like getting enough sleeping, eating a balanced diet, and exercising regularly will not only help you lose weight more easily. Making healthy lifestyle choices is also the best way to prevent chronic conditions like heart disease, diabetes, and many types of cancer.

If you’ve been struggling to sleep at night, here are some quick and easy tips you may want to try: