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Medical Offices of Manhattan

Medical Offices of Manhattan’s Primary Care Physician, Lisa Alex,MD, speaks to LiveStrong about the link between sleep and weight loss.

What are the recommended hours of sleep each night?

While needs vary from person to person, most people function best at 7 to 9 hours of sleep every night.

What are some factors that may contribute to how many hours of sleep you should get each night?

There are set factors like age and genetics. Generally, kids and teens need more sleep than adults, but you typically need the same amount of sleep when you’re a young versus older adult. More personal factors include preference and simply sleepiness. The best way to figure out your sleep needs is if you can let yourself sleep naturally for a few days to a week, going to bed when you are tired and waking up whenever is natural.

How is sleep and weight loss connected? In what ways does sleep contribute to/promote weight loss?

Bad sleep decreases the effectiveness of the body’s metabolism. It leaves more unexpended energy to be stored in the body as fat. Furthermore, research indicates that sleep deprivation lowers your resting metabolic rate, which is the calories your body burns when it is at rest. Good sleep helps prevent insulin resistance. Insulin is the hormone responsible for moving sugar from the blood to cells to be used as energy. And when cells resist insulin, you become hungrier. Your body responds by storing more calories as fat.

She is quoted saying:
“Sleep deprivation also negatively affects the prefrontal cortex of the brain, which is responsible for impulse control and helping you make healthy decisions, according to Dr. Alex. So, not only can sleep deprivation cause you to crave more unhealthy foods, but it also can impair your ability to resist indulging in them.”

How is sleep connected to fat metabolism? How does this affect weight/weight loss?

Although no direct correlation is seen with sleep deprivation and obesity, we definitely see strong associations between the two. When we do not sleep an adequate amount each night (~7 hrs), studies have shown that lack of sleep is associated with alterations in certain hormones like leptin and ghrelin, along with increased hunger and appetite.

How is sleep connected to gut health? How may this affect your weight or weight loss?

Your intestine hosts your body’s largest concentration of microorganisms, called the microbiome. It is home to a nervous system that is in constant communication with the rest of our body, much like the brain. So it helps regulate our hormones, digestion, metabolism, appetites and more. Research shows that inadequate sleep quickly has negative effects on the microbiome. Studies have shown that sleep deprivation causes significant decreases in your gut’s beneficial bacteria and even changes the composition of some microorganisms that are linked to obesity and type 2 diabetes.

Because sleep affects your microbiome, which affects metabolic health, it definitely can play a role in your weight loss goals.

Is there any validity behind the idea that sleep affecting cravings? How does this work and how may it affect weight?

Leptin is a hormone that signals to our brain that we are no longer hungry and are satiated, but that becomes decreased with lack of sleep. Thus, we feel more hungry and consume more calories.

She is quoted saying:
“While your leptin levels decrease with sleep deprivation, your ghrelin levels go up. Ghrelin is a hormone that increases feelings of hunger, causing your body to crave and consume more calorie-rich food in an attempt to compensate for your lack of energy.”

When trying to lose weight, despite efforts of trying to exercise and maintain a healthy diet, our bodies will not register when it is deprived of adequate sleep. Lack of sleep has also been noted to reduce the portion of the weight loss, despite calorie restriction. This may be due to the body registering the “need” for fat as an energy source and despite efforts, a decreased ability to lose weight.

Read the original article on LiveStrong.