A little nighttime reading

Sleep and metabolism: How does sleep affect weight loss?

Everybody knows diet and exercise have a major impact on weight and metabolism. But do you know how important sleep is to the weight loss equation? Or that lack of sleep may actually be the culprit behind a growing waistline?

Sleep and metabolism are very much connected. Whether you’re looking to simply maintain a healthy weight or seriously shed some pounds, prioritizing sleep is a smart strategy.

A study of 1,000 people found that the folks who slept less were more likely to weigh more. This correlation isn’t surprising. Sleep (or lack of it) plays a key role in the systems of your body that affect weight. Sleep helps maintain a healthy metabolism, regulate hormones and stimulate detoxification.

The relationship between sleep and weight loss is multi-faceted, so how exactly does sleep affect weight loss? Read on to find out more.

Sleep’s effect on appetite
Sleep is intimately associated with our endocrine system, the collection of glands that produces hormones responsible for metabolism (among many other functions). A number of studies reveal the various ways lack of sleep disrupts the normal functioning of this system.

Lack of sleep will make you hungrier
Sleep deprivation compromises your fat cells’ ability to use insulin, which in turn throws your “hunger hormones” out of whack. For example, when we don’t get enough sleep, the levels of ghrelin in our bodies increase. Ghrelin is a growth hormone that boosts appetite and fat production. Conversely, lack of sleep causes levels of leptin to decrease. Leptin is a hormone that curbs hunger and signals to your body that it’s satiated. Basically when you haven’t slept enough, you’ll feel hungrier, and it’ll take more food to feel full. Even worse, chronic long-term sleep deprivation promotes insulin resistance, a risk factor for obesity and diabetes.

You’ll crave fatty, high-carb foods
It becomes harder to maintain self-control during those times when we don’t get enough sleep. A tired brain craves substances that provide feel-good comfort. A study published in the American Journal of Clinical Nutrition showed volunteers were more prone to snacking on high-calorie, high carb foods when sleep deprived, while a University of Chicago study revealed that people choose higher-fat foods when lacking sleep.

You won’t have the energy and drive to keep fit
Finally, a poor sleep schedule can also mess up your cortisol levels, causing spikes at inappropriate times. Cortisol is the “stress hormone” that tells your body to conserve energy to fuel your waking hours. If your cortisol levels are abnormal, this can signal your body to hold on to fat and trigger blood sugar crashes. Over time, elevated cortisol levels leads to adrenal fatigue, a condition that causes fatigue, body aches and digestive problems.

“Sleep hormone” melatonin and your ability to torch calories
Your brain’s pineal gland secretes the hormone melatonin, which regulates your circadian rhythm (ie: your “body clock”) to determine when you fall asleep and wake up. A study with rodents found a correlation between higher levels of melatonin and activated brown fat. The research indicates that melatonin lowers obesity levels, irrespective of activity and food intake, which suggests that the brown fat is helping weight loss.

If you’ve never heard of brown fat, this is a type of fat everybody has which, opposed to white fat, actually helps you burn energy and calories.

To boost your levels of melatonin (and subsequently your levels of brown fat):

    • Get plenty of sunlight during the day
    • Go to bed before 11 pm
    • Meditate, journal, stretch or take a warm bath -- all activities that will alleviate stress before bedtime

Additionally, a study published in Diabetes indicated that just turning down the thermostat to a sleep-appropriate 66℉ can help your body produce more energy-burning brown fat. Study participants doubled their volumes of brown fat after only four weeks of sleeping at this cooler temperature.

Obesity’s link to sleep apnea
The most sleep-starved folks are often those with sleep apnea, a condition that affects over 18 million US adults. It’s believed this number is far higher for a condition considered heavily underdiagnosed. Sleep apnea is a serious sleep disorder where a person’s breathing is disrupted throughout the night (sometimes hundreds of times), depriving the brain of oxygen. This disorder can lead to heart disease, Type 2 diabetes, acid reflux, high blood pressure, depression and asthma. A telltale sign of having sleep apnea is chronic, heavy snoring.

One of the biggest contributing factors to sleep apnea is obesity. It’s estimated that between 25% - 45% of obese adults have obstructive sleep apnea. When you’re overweight, fatty deposits in your neck can block breathing and obstruct your air passages.

The Catch-22 is that as sleep apnea keeps you from getting restful sleep, it then disrupts your hormones -- which in turn contributes to weight gain. Sleep apnea sufferers often fail to get enough sleep that provides the energy to power through workouts or fight food cravings.

Exercise and diet to help lose weight can help alleviate sleep apnea, but we also recommend seeing a sleep specialist for more insight if you suspect you have the disorder. There are a number of treatment protocols that will address the problem.

Make sleep an essential component of overall wellness and fitness
These are just some of the ways in which sleep has been linked to metabolism and weight. So now, aside from keeping a healthy diet and sticking to a fitness regimen, consider how you can make high quality sleep a priority in your weight management game plan.

Ready to tackle that muffin top by improving your sleep self? Slumbr has a variety of tips for getting better quality shuteye.

Photo credit: © Can Stock Photo / sidelnikov