By Todd Norwood, PT, DPT
This edition covers:
Diet and exercise are the top two factors many consider when managing weight. Rightfully so, as the combination of diet and exercise has a strong influence on our overall energy balance. But there’s a third modifiable behavior that flies under the radar, yet is arguably the most important conduit to weight health: sleep.
The impact of sleep on weight and body composition is perhaps as surprising as it is significant. The weekly recommended amount of sleep for optimal health exceeds the weekly time recommended for physical activity by a wide margin — 49 to 63 hours of sleep compared to just two and a half hours of exercise. This disparity begs the question:
Why does the amount of time we spend in a state of rest have such significant effects on our weight health?
Sleep can influence our body composition when we are losing weight. A 2010 study demonstrated that individuals in negative energy balance lost 60% more muscle mass and 55% less fat mass when only allowed to sleep for five and a half hours each night over a two-week period. This was compared to a group who was allowed to sleep eight and a half hours each night for the same period.
One reason for this finding may be that lack of sleep shifts the balance of muscle protein synthesis and muscle protein breakdown in favor of the latter, which ultimately leads to the loss of muscle mass. It is believed that processes essential to the maintenance of muscle mass occur during sleep, and thus a reduction of sleep impairs these processes.
Given the importance of maintaining lean body mass while losing weight, especially if using GLP-1s to do so, ensuring adequate sleep is critical to achieving optimal health and weight maintenance.
Adults need at least seven hours of sleep each night, on average, but each individual is different. Some will do well with seven hours, while others may need nine or more hours of sleep to function at their best. However, one-third of U.S. adults report getting less than seven hours of sleep each night.
Lack of sleep can result in fatigue and drowsiness in the near term, but may lead to more profound health consequences in the long term, such as increased risk for obesity, diabetes, high blood pressure, heart disease, and stroke. Reductions in sleep quantity and quality can arise for a multitude of reasons. Some are lifestyle factors such as the consumption of caffeinated beverages late in the day, while others are related to our stage of life such as pregnancy, welcoming a new child, and menopause.
Other reasons one may not attain the recommended amount of sleep each night are sleep disorders, which affect an estimated 50 to 70 million individuals in the U.S. The most common sleep disorder is insomnia, however, the second most prevalent sleep disorder is obstructive sleep apnea (OSA) — a condition linked to higher BMI.
In fact, a 10% increase in body weight is associated with a six-fold increase in the likelihood of OSA.
It is believed that between 10 to 30% of U.S. adults struggle with OSA, but many are undiagnosed. The disruptions in sleep caused by OSA are linked to a higher risk of diverse health issues, including depression, nonalcoholic fatty liver disease, and anesthesia-related complications, among others.
Further, U.S. adults report losing almost one hour of sleep each night due to pain, with 56% of individuals attributing it to back pain. Interestingly, the relationship between sleep and pain is a two-way street in which reductions in sleep can increase the perception of pain, and pain can cause insomnia. This highlights the importance of musculoskeletal (MSK) health in both sleep and weight management.
When it comes to achieving and maintaining a healthy weight, sleep should be considered a key pillar to success, along with diet and exercise. At Omada, we support our members in achieving their best health outcomes with a multifaceted approach to weight maintenance, integrating evidence and best practices around diet, aerobic and resistance exercise, sleep, and physical therapy for those experiencing musculoskeletal pain.