Lack of sleep may increase body weight

Posted by .(JavaScript must be enabled to view this email address)
Monday, January 10, 2005 11:03 am Email this article
Lack of sleep is associated with a higher body weight according to a new study. One hour less sleep per week was associated with an increase in BMI of 5.4 units.

Here is the total sleep time for men and women.

                                                       

MEN   Sleep Time versus Body Weight
Weight	Sleep Time	Difference
Normal Weight	7 hrs 53 min	Not Applicable
Overweight	7 hrs 34 min	19 min less per day
Obese	7 hrs 49 min	4 min less per day
Extremely Obese	7 hrs 45 min	8 min less per day

                                                       

WOMEN Sleep Time versus Body Weight
Weight	Sleep Time	Difference
Normal Weight	8 hrs 3 min	Not Applicable
Overweight	8 hrs 2 min	1 min less per day
Obese	7 hrs 14 min	49 min less per day
Extremely Obese	7 hrs 56 min	75 min less per day

The effect of medical conditions on sleep time

Obese patients with an average body mass index (BMI) of 32 slept 16 minutes per day less than normal weight patients with an average BMI of 22.

This is a total of 1.9 hours per week less sleep.

One hour less sleep per week associated with 5.4 increase in BMI

This means that each one hour less sleep is associated with an increase in BMI of 5.4 units.

Nightshift associated with 42 minutes less sleep per day

Nightshift work was associated with 42 minutes less total sleep time per day.

Previous studies have found that nightshift workers have higher body weights than people who work days.

Evening shift, smoking, caffeine, weight loss products not associated with less sleep

Evening shift work, smoking, caffeine, and weight loss products did not affect total sleep time.

The effect of medical conditions on sleep time

The following medical conditions are associated with less sleep time.

• Arthritis: 7 minutes less sleep per day
• Asthma: 13 minutes more sleep per day
• Coronary Artery Disease: 24 minutes more sleep per day
• Diabetes: 1 minutes more sleep per day
• Gastroesophogeal Reflux Disease: 2 minutes less sleep per day
• Hypertension: 2 minutes less sleep per day

Reasons lack of sleep may increase body weight

Less sleep may increase body weight for the following reasons according to the paper.

Lack of sleep lowers glucose tolerance

Lack of sleep in young, healthy men reduced glucose tolerance, reduced glucose effectiveness, and acute insulin response to glucose.

Lack of sleep increases stress hormone, cortisol

It also increased stress hormone levels—cortisol levels—at night, and reduced the rise in thyroid-releasing hormone at night as well as the total released throughout the day.

Lack of sleep lowers growth hormone

Lack of sleep also has been found to reduced growth hormone secretion in young, healthy men, which may impair blood sugar control, as well as body composition.

Lack of sleep lowers leptin

Less sleep also reduces the hormone leptin, which normally has an appetite-reducing effect.

Conclusion: An extra 20 minutes of sleep a night might lower BMI

“We caution that this study does not establish a cause-and-effect relationship between restricted sleep and obesity… [but] Our findings suggest that major extensions of sleep time may not be necessary, as an extra 20 minutes of sleep per night seems to be associated with a lower BMI,” the authors conclude.

Subects: 1,001 people, 18-91 years old

The study involved 1001 individuals, 18- to 91-years-old, who were recruited from four primary care practices in the southeastern portion of Virginia.

Comments: I wish they would have measured sleep quality

I hope in a future study they measure sleep quality and how it relates to body weight.

If I sleep 8 hours straight through I feel much better than if I wake up numerous times.

I would not be surprised if normal weight people have better quality sleep than obese people also.

Comments: Sleep deficit, caused by artificial lighting, is linked to heart disease, cancer, diabetes, and obesity according to the book “Lights Out” says

I read a great book a couple of years ago called “Lights Out” by T. S. Wiley and Bent Formby PhD.

They suggest sleep deficit—often caused by artificial lighting—is linked to heart disease, cancer, diabetes, and obesity.

They say that artificial lighting—lamps, television, and computer monitors—causes us to sleep less than we normally would in the winter.

Comments: Prior to 1910, we slept 9-10 hours per day, 14 hours in the winter

They say that prior to 1910 before the use of artificial light we used to sleep 9-10 hours per day and now we average about 7 hours. In 2001, I saw a female sleep researcher on the Discovery channel saying that without artificial lighting we would normally sleep 14 hours a night in the winter.

Comments: Artificial lighting causes lack of sleep and overeating

The book says that artificial lighting causes us to overeat because leaving the lights, television and computer on until late at night tricks our brain into thinking it is the long days of summer and that we need to fatten up for the coming winter when it will be difficult to find food, but this never happens so we end up overeating all year round.

Comments: Turn the lights, computer and TV off early

They recommend turning lights off early in the evening, and turning off the computer early also.

Comments: Totally blacken your bedroom

They also recommend completely blackening out the room where you sleep; the room should be so black that you cannot see your hand in front of your face.

After reading this book, I realized that it takes me 3 hours to get to sleep after I get off the computer.

Warning: I hated the writing style of this book

Warning: I hated the writing style of this book, but I was fascinated by the information they presented. They seem to love to use long sentences with lots of qualifying phrases. I often found myself having to re-read sentences because by the time I got to the end of the sentence and through all the qualifying phrases, I could not remember what the sentence was about. It took me about 50 pages to get past the writing style and focus on the content. Two smart friends of mine, both who are avid readers—one a physicist and the other a doctor—did not finished the book, I believe, because of the writing style. If you are looking for a fun book to read, this is not it. But, if you are looking for an interesting book, that you don’t mind having to struggle through, I would highly recommend it.

REFERENCE

Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med. 2005 Jan 10, 165(1):25-30.

AUTHOR’S CONTACT INFORMATION

Robert D. Vorona, MD
Sentara Norfolk General Hospital
600 Gresham Dr
Norfolk, VA 23507
.(JavaScript must be enabled to view this email address)

Articles on the same subject can be found here:

• Sleep