Over one billion adults worldwide are classified as overweight (BMI 25 to 29.9 kg/m) or obese (BMI > 30 kg/m). Genetics, inactivity, and high-fat diets contribute to obesity. Yet, the role of sleep in weight loss is often overlooked. In the last 30 years, average adult sleep has dropped from 8.5 to 7.2 hours, with rising sleep-related problems.
Just How Important is Sleep?
Sleep is one of the most important factors in maintaining a healthy lifestyle – it is just as vital for weight loss as diet and exercise. In fact, getting a proper night’s rest can improve metabolism, reduce stress levels, and boost moods.
Around 25% of the population in the United States is currently experiencing sleep deprivation, and this decrease in sleep duration has corresponded with an increase in obesity rates. Research shows that sleep deprivation alters metabolism in a manner that makes individuals more prone to weight gain. Leptin regulates body fat, and ghrelin stimulates appetite, with key roles in weight regulation. These hormones link sleep duration to BMI: insufficient sleep reduces leptin and increases ghrelin, raising appetite and potentially causing obesity.
Exploring the Link Between Sleep and Weight Loss: Insights from Scientific Studies
The following studiesdelve into the intricate and multifaceted relationship between sleep and weight gain. Keep reading to learn what roles genetics, environment, and sleep duration play in obesity.
Associations between short sleep duration and central obesity in Women
Women with a larger waist size may be sleeping less, according to a study by Theorell-Haglöw et al. This places them at a higher risk of developing central obesity, which has a stronger link to heart disease, diabetes, and mortality compared to BMI. This study was the first to use full-night polysomnography instead of self-reported sleep durations and included 400 women between the ages of 20 and 70 in Sweden. According to its findings, the less a woman slept, the larger her waist circumference and sagittal abdominal diameter were. The study also concluded that younger women under the Age of 50 had a stronger association between sleep duration and central obesity.1
Twin Study of Sleep Duration and Body Mass Index
In a twin study led by N. Watson et al., after careful genetic and environmental adjustments, short sleep correlated with increased BMI. People sleeping less than seven hours per night tended to have higher body weight than those with seven to eight and a half hours, particularly in twins sharing the same environment. The study indicates that this sleep-weight connection arises from environmental factors, such as lifestyle and habits, rather than genetics. Examining Seattle twins reporting height, weight, and sleep duration, there was minimal evidence suggesting a genetic influence on the sleep-body mass link.2
Association of Short Sleep Duration with Weight Gain and Obesity
A Japanese study of 35,000 electric company employees found a strong connection between short sleep and weight gain. Men sleeping less than five to six hours a night had a higher risk of obesity, with nearly 6% of non-obese men becoming obese within a year due to insufficient sleep.3 Those sleeping less than six hours a night were at an even greater risk.
Sleep to Lose Weight?
For those of us thinking it might be easy to trim down by simply adding an hour or two of sleep back into our daily routine, the solution is unfortunately not quite that simple. More studies need to be done to determine the nature and direction of the association between sleep and obesity. The obesity epidemic requires a multidisciplinary approach encompassing stress management, reduction of risky behaviors, and increase in healthy lifestyle habits. One of those healthy habits – adequate sleep – is a key factor in the equation.
Somnology offers a comprehensive approach to sleep care, utilizing services like SLaaS® (Sleep Lab as a Service), telemedicine, SomnoRing®, and the SomnologyMD mobile app to bring sleep lab technology and expertise directly to users, streamlining the care experience. The patient is at the center of our priorities as we proactively guide them through their sleep care journey. Visit our website to learn more.
Sources:
- Theorell-Haglöw J, Berne C, Janson C, Sahlin C, Lindberg E., Associations between short sleep duration and central obesity in women, Sleep. 2010 May 1;33(5):593–598.
- Watson NF, Buchwald D, Vitiello MV, Noonan C, Goldberg J., A Twin Study of Sleep Duration and Body Mass Index, Journal of Clinical Sleep Medicine, 2010 Feb 15;6(1):11–17.
- Watanabe M, Kikuchi H, Tanaka K, Takahashi M., Association of short sleep duration with weight gain and obesity at 1-year follow-up: a large-scale prospective study, Sleep, 2010 Feb 1;33(2):161–167.