As many of us struggle with the time change today - we can keep in mind that at least 13% of Americans report regularly having "excessive daytime sleepiness" (EDS), which has increased from 10% in 2002.2
Much of the problem comes from insufficient sleep and associated sleep disorders, of which 50 to 70 million people suffer.4 Also, many of us do not get the recommended amout of quality sleep each night.
Subsequently, "short and long sleep duration are associated with up to a 2-fold increased risk of obesity, diabetes, hypertension, cardiovascular disease, stroke, depression, substance abuse, and all-cause mortality [death]."4
How to Measure EDS
Those with EDS would answer higher to the following questions, resulting in a higher total score.3
How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired?
Use the following scale to answer each item below.
0 = would never doze
1 = slight chance of dozing
2 = moderate chance of dozing
3 = high chance of dozing
- Sitting and reading ____
- Watching TV ____
- Sitting, inactive in a public place (e.g. a theater or a meeting) ____
- As a passenger in a car for an hour without a break ____
- Lying down to rest in the afternoon when circumstances permit ____
- Sitting and talking to someone ____
- Sitting quietly after a lunch without alcohol ____
- In a car, while stopped for a few minutes in traffic ____
A total score of 15 or higher indicates high levels of daytime sleepiness.
Body Weight and EDS
Next to depression, our body weight is a leading predictor to EDS.1 A higher body mass index (BMI) can double one’s odds of having EDS. In comparison, depression was related to nearly 7 times the odds. On the other hand, getting enough quality sleep at night is protective against EDS. Interestingly, excess body weight and EDS are also main predictors of depression.5
As shown in the following figure, EDS really starts to increase in those with a BMI of 28 or greater.1
- A 5’5” person weighing 168 pounds would have a BMI of 28.
- A 5’10” person weighting 195 pounds would also have a BMI of 28.
You can use this BMI calculator to find your current BMI.
Weight Loss Effect on EDS
Since adults classified as overweight or obese report higher levels of daytime sleepiness, a recent review of all previous research determined if intentional weight loss can improve EDS.6
They found a total of 44 studies that examined both surgical and non-surgical weight loss effects on daytime sleepiness.
“This review concludes, for the first time, that surgical and non-surgical weight loss interventions in those who are overweight or obese are likely to benefit daytime sleepiness.”
However, the authors found an J-shaped relationship between the amount of weight loss and daytime sleepiness, “which means that daytime sleepiness improved with weight loss, but the rate of this improvement decreased with increasing magnitude of weight loss.”
You can see in the figure below, the biggest drop in sleepiness occurred in early weight loss. Larger amounts of weight loss did not benefit EDS as much. Notice that as the amount of weight loss went past 5-10 kg (11-22 lbs), the effect on sleepiness became less pronounced (i.e. weaker), and begins to level out.
In conclusion, excess body weight can increase excessive daytime sleepiness (EDS), while weight loss can improve EDS. It is encouraging that EDS is improved quite quickly as the weight begins to come off, and that we do not have to lose a bunch of weight to experience these improvements.
Also, we cannot rule out a vicious cycle where EDS can lead to excess weight, especially as EDS has been shown to relate to lower physical activity and poorer dietary intake.
- Bixler, E. O., Vgontzas, A. N., Lin, H. M., Calhoun, S. L., Vela-Bueno, A., & Kales, A. (2005). Excessive daytime sleepiness in a general population sample: the role of sleep apnea, age, obesity, diabetes, and depression. The Journal of Clinical Endocrinology & Metabolism, 90(8), 4510-4515.
- Ford, E. S., Cunningham, T. J., Giles, W. H., & Croft, J. B. (2015). Trends in insomnia and excessive daytime sleepiness among US adults from 2002 to 2012. Sleep medicine, 16(3), 372-378.
- Johns, M. W. (1991). A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep, 14(6), 540-545.
- Kalliny, M., & McKenzie, J. G. (2017). Occupational Health and Sleep Issues in Underserved Populations. Primary Care: Clinics in Office Practice, 44(1), e73-e97.
- LaGrotte, C., Fernandez-Mendoza, J., Calhoun, S. L., Liao, D., Bixler, E. O., & Vgontzas, A. N. (2016). The relative association of obstructive sleep apnea, obesity and excessive daytime sleepiness with incident depression: a longitudinal, population-based study. International Journal of Obesity.
- Ng, W. L., Stevenson, C. E., Wong, E., Tanamas, S., Boelsen‐Robinson, T., Shaw, J. E., ... & Peeters, A. (2017). Does intentional weight loss improve daytime sleepiness? A systematic review and meta‐analysis. Obesity Reviews, 18(4), 460-475.