Sleep Less, Eat More?

Ant writes "A study, published Monday, found that people who sleep less tend to be fat, and experts said it's time to find if more sleep will fight obesity. Monday's study from Eastern Virginia Medical School in Norfolk covered 1,000 people and found that total sleep time decreased as body mass index -- a measure of weight based on height -- increased. Men slept an average of 27 minutes less than women and overweight and obese patients slept less than patients with normal weights, it said. In general the fatter subjects slept about 1.8 hours a week less than those with normal weights."

Comments

The obvious?

[BWJones]

Ummm, yeah. I talked about this in my journal some time ago back in November. And yes, I used to run a sleep lab, so I feel validated in commenting on this from a medical perspective. At any rate, there were some serious problems with this study in terms of proper controls, including analysis of sleep disordered breathing (causing sleeplessness) that may in of itself be due to pre existing obesity. However, the simplest explanation could be the obvious one which the original poster commented on in the title and that John Harrison also got in a comment in my journal: Sleeping less means more time available for eating! Simple correlative studies are rarely terribly valuable, but on topics as important or as commonly dealt with including obesity, cancer and heart disease always get a fair bit of press.

Granted, studies with large numbers of people in them tend to be expensive and are the only way to detect small variances in the population, but I often think the money would be better spent on smaller, more thorough, better designed studies with more controls and experimental conditions.

Re:The obvious?

[Mr. Slippery]

Sleeping less means more time available for eating!

Maybe, but I would suspect that stress may play a role: inadequate sleep means a stressed organism. Stress messes with body chemistry in ways that have been linked to obesity - and obesity itself is a stressor, creating a feedback loop. People also often turn to "comfort food" when stressed.

There have been high-stress low-sleep times in my life when I've tried to substitute food for sleep; fortunately I was aware enough to see what I was doing and restore my old eating habits after the stress had passed and sleep patterns were more normal.

Re:The obvious?

[jburroug]

Sleeping less means more time available for eating!

There are other obvious explanations as well, such as getting insuffient rest leads to less energy/motivation to exercise.

I (in theory) keep a pretty regular workout schedule, running a couple/three times a week and a little light free weight work every other night. When, for whatever reason, I get less sleep than usual the night before I find it very difficult, sometimes impossible, to summon the motivation to get off the couch and go out for my run or pick up the weights. That and when I do win the battle on sleepy days my performance sucks, I lose a couple of reps on the weights or I never feel like I'm hitting my stride when running. And on days where I'm really dragging after work I head right for the high-calorie, easy to prepare option for dinner instead of putting in the effort to make something better for me.

Of course as some other posters have pointed out the relationship between obesity and sleeplessness could be reversed, it's harder to get a good night sleep when you're obsese because of the other health problems associated with obesity. I'm betting on it being one of those vicous cycle things: it's harder to live healthy when you're not well rested and it's harder to sleep well when you're not living healthy... ad infinitum.

To add more anecdotal evidence to the argument. When I do get in a good run after work I sleep like a rock and usually go to bed 30-60 minutes earlier. So I'm better rested the next night, which makes it easier to keep working out and eating better, which makes it easier to work out... ad infinitum.

Misleading headline

[Space cowboy]

Even the scientists aren't claiming this:

"We caution that this study does not establish a cause-and-effect relationship between restricted sleep and obesity (but) investigations demonstrating success in weight loss via extensions of sleep would help greatly to establish such a relationship."

Noting that states A and B appear to have a mutual relationship does not mean that A implies B, it could just as easily mean that B implies A, or even that the statistics are skewed by something else...

If it turns out that fat people have more trouble sleeping than thin ones, then they would sleep less, but trying to force them to sleep more (drugs perhaps) would not necessarily decrease their weight...

Simon

uh oh, here it comes

[frogger01]

now all the crazy fat mcdonalds eating american fatties are going to be sleeping in, but instead of being lazy, they'll be 'on diets'

Sleep Apnea (OSA)

[dolo666]

I have sleep apnea and I will testify before you all that because of significant sleep deprivation during my youth, I had to eat foods that were:

a) Rich in sugar or grease
b) Fast and easy to prepare

If these conditions aren't met, I could not function very well, even with CPAP.

I was born with an unusually narrow throat, and I spent most of my early childhood as a beanpole -- I was super skinny. But after years of chronic apnea, due to the OSA, I slowly grew... and then suddenly I became super-sized.

I would daydream in class (ie: getting my waking REM), and even fall asleep during lectures.

I had zero energy, so I drank a pot of coffee in the morning and one in the afternoon, along with cigarettes to speed my heart up and get me going. I could never have graduated from school without doing this. Society requires that everyone must perform at a uniformed level, unless you have a disability, but my disability was never discovered until I was 30yrs. That's 30yrs of health slippage....

The point is... people with sleeping disorders need to have the disorders fixed, but the current CPAP machines are really not a solution -- they aren't ready to combat the seasons properly and they are horrible for people with dust allergies.

Until a solution for apnea is found and people realize that being overweight is not the cause, but a symptom -- people with apnea and other sleeping disorders won't be very healthy (mentally, emotionally or physically).

I got out of bed for this?!

[QuantumG]

Wake me when I'm thin.

Coritsol and stress

[wowbagger]

There are some studies that link high cortisol levels (due to stress) with an increased chance of obesity.

Could it be simply that people who got enough sleep were less stressed?

Exercise and Sleep

[Mudd Chick]

Some of it might have to do with the relationship between obesity and lack of exercise. When I am on a regular exercise regime, I find myself forced to sleep 7 or 8 hours a night rather than 5 or 6 -- otherwise I feel completely exhausted. Sedentary people may be able to get by on less sleep than the physically active.

This is easily explained, actually.

[Xaroth]

Without having read TFA, I can already say that this is fairly obvious if you think about it.

When you start to get tired, you feel low-energy. When you feel low-energy, you eat "quick energy" foods - those that are readily metabolized and high in calories. It's your body saying "Oh, crap! We don't have enough energy right now! Do something about it!" (This is due to falling glucose levels in the brain as you get tired, but I'm sure that's covered in TFA.)

Of course, you don't really need the energy, you need sleep. The result is that you take in waaay more calories than your body actually uses. The more sleep deprived you are, the more this happens.

It makes me wonder if there's a causal relationship between the decreasing amount of sleep your average American (and, indeed, member of any industrialized nation) gets and the increases seen in obesity.

Oooh, cause and effect

[bigberk]

The article mentions, correctly, that this does imply any cause-effect relationship. As a bit of a health nut, here are some of the possibilities I have thought of regarding the relationsip between sleep and being overweight/unhealthy:

• People with irregular daily routines might not sleep as much as they need to, and similarly, may skip meals or snack excessively which is known to lead to unhealthy weights
• Stressful lifestyles both impact sleep cycles, and one's diet and exercise routine (stress leading to unhealthiness)
• People who are overweight may have trouble sleeping due to breathing difficulties, or other discomforts arising from a general lack of good health
• People who are well disciplined may be better at adhering to exercise and healthy eating routines, and similarly, sticking to proper sleeping patterns and allocating enough hours for a good night's sleep.

get more exercise

[caviare]

That there is a correlation between getting enough exercise and being of normal weight is well known. Isn't there also a correlation between being getting enough exercise and sleeping well? Wouldn't these two correlations explain the observed results? "Get more exercise then you'll both lose weight and sleep better" seems more likely to me to be causal relationships, than "try and sleep better and then you'll lose weight".

Sugar is the Real Culprit

[stankulp]

All of the fad diets that actually worked over the past two or three decades have one thing in common: DON'T EAT SUGAR.

The "Eat to Win" diet of the '80s was a high carbohydrate, low protein, moderate fat diet that worked. The guy who invented it was Martina Natrilova's trainer, and it worked for her.

The Atkins diet is just the opposite, low carbohydrate, moderate fat and high protein, and it works too.

Both these diets work as long as the dieter actually follows them.

The one thing they have in common is DON'T EAT SUGAR. Don't drink sugary caffeinated beverages. Don't eat ice cream. Don't eat candy bars. Don't eat donuts.

The really bad thing is that eating sugar makes you hungry.

It's not rocket science, but it's harder than Hell to give up sweets if you have a sweet tooth.