By Blake and Gwen Beckcom

With almost 71 percent of U.S. adults over the age of 20 being overweight or obese, obesity is a major epidemic in the U.S. Additionally, almost 21 percent of children between the ages of 12 and 19 are considered obese; 17 percent of 6- to 11-year-olds and 9 percent of 2- to 5-year-olds are fighting the same battle.

Diet and exercise play a huge role in this problem, but many people do not realize that sleep is a large factor as well.

Sleep deprivation is very common — a reported 50 to 70 million adults suffer from a sleep disorder. More than 35 percent of adults report that they get less than seven hours of sleep each night.

This lack of sleep has serious consequences such as fatigue, but it may also have an impact on your weight.

Better sleep = lower weight

Studies have shown that sleep duration is negatively associated with body mass index (BMI) and waist circumference, suggesting that the longer a person sleeps, the smaller their waist and lower their BMI tends to be.

In fact, people who sleep approximately six hours per night tend to have a waist circumference more than 1 inch larger than those who have nine hours of sleep. A lower amount of sleep has also been linked to lower levels of beneficial cholesterol and a higher likelihood of obesity, which comes with much comorbidity.

Studies have also found that sleeping longer on the weekends may positively impact weight. People who slept an additional two hours on weekend days than they did on weekdays were found to have a significantly lower BMI than those who do not catch up on their sleep over the weekend.

Sleep deprivation has a strong influence on hormone levels — including increasing ghrelin — which increases hunger and decreasing leptin; the latter is a hormone which helps your body know it’s full.

Sleep and waistline

Sleep allows your body to function properly. If you don’t get enough, your self-control and willpower may suffer, which will likely cause you to make unhealthy eating choices.

Biologically speaking, a lack of sleep disrupts important hormones and metabolic function. If you lose as little as 30 minutes of sleep every night, you can disrupt your metabolism just enough to gain weight.

For every half-hour of sleep debt that you get during weeknights, your risk for obesity and insulin resistance is increased by up to 39 percent after one year.

This means if you only get seven hours — out of the recommended eight — you could raise your risk of obesity by 34 percent and chances of insulin resistance by 78 percent. Studies have also shown that people who sleep only five hours a night tend to gain almost two pounds a week due to increased calorie consumption.

Alternatively, adults and children who sleep nine hours a night tend to have a constant weight and eat fewer unhealthy foods. If weight loss is your goal, it is important to make sure you are getting enough sleep; otherwise, your dietary interventions to lose weight may be compromised.

How much is enough?

Approximately one third of Americans get under seven hours of sleep each night, and more than 83 million adults in the U.S. are sleep-deprived. In addition to weight gain, not getting enough sleep can result in diseases such as type 2 diabetes and metabolic syndrome. It can also interfere with thyroid hormones and promote inflammation in the body. Sleep deprivation can affect the immune system similarly to physical stress and illness, which helps explain why sleep deprivation is tied to an increased risk of chronic disease and acute illness.

If you are not sure if you are sleep deprived, here’s a test: go to your bedroom in the afternoon to take a nap and hold a spoon over the side of the bed.

Place a metal tray next to the bed so when you fall asleep the spoon will fall out of your hand, hit the tray and wake you up. If this happens in less than five minutes, you’re severely sleep deprived. If it takes 10 minutes, you could still likely use more sleep. However, if you stay awake for over 15 minutes, you are likely well-rested.

Lucky number eight

How much sleep you need will depend on your age, your level of activity, and your overall health, but the average goal is eight hours.

Keep in mind that this means more than just being in bed for eight hours — you have to actually be asleep for that amount of time.

You can use a fitness-tracking device — such as a FitBit — to gather data about each night’s sleep patterns. If you need improvement, take a look at your sleep hygiene.

Sleep hygiene includes your sleeping environment, your regimen prior to going to bed, and the schedule of your exposure to light.

Enough exposure of bright light throughout the day regulates your circadian rhythm to ensure that your body is producing the right amount of melatonin. In the evening, limit your exposure to light by turning off electronic devices and switching to low-wattage light bulbs or candles.

Overall, if you are able to get enough sleep, you will be more likely to lose weight. Keep in mind that sleep is as important as diet and exercise when trying to maintain a healthy weight.

—Blake and Gwen Beckcom run Fitness Together Mission Hills. Contact them at fitnesstogether.com/missionhills or call 619-794-0014.