Teen Obesity: Lack of Exercise May Not Be to Blame

[The Straight Story]

Teen Obesity: Lack of Exercise May Not Be to Blame

....

That's precisely why the findings of a new study by researchers at the Johns Hopkins Bloomberg School of Public Health came as such a surprise. The report, published last week in the journal Obesity Reviews, finds that the amount of physical activity among U.S. teens has not in fact changed significantly over the past two decades, even while that population has gotten heavier. "On the one hand, we have seen the obesity-prevalence increase, but we don't see a decrease in physical activity," says Dr. Youfa Wang, an associate professor at the Center for Human Nutrition at Hopkins and lead author of the study. "This suggests that physical activity is not a good explanation for the increase in prevalence of obesity."

In simple terms, body weight is a reflection of the balance between two variables: the calories a body takes in and the calories it burns off. As far as the average U.S. teen is concerned, the study suggests, the culprit behind weight gain is not a decrease in exercise but an increase in consumption. Of course, that doesn't mean teens are getting adequate exercise: Wang analyzed data from nearly 16,000 high school students between the ages of 15 and 18, who took part in the Centers for Disease Control and Prevention's longitudinal Youth Risk Behavior Surveillance Survey, about their physical activity. He and his team found that in 2007, only 34.7% of teens met federal physical activity recommendations, which call for activity strenuous enough to cause heavy breathing for a total of an hour a day for five or more days a week. (See nine kid foods to avoid.)

But the survey also found that teens' overall rate of daily exercise had not changed much since 1991, when the study sample was first asked to report their participation in gym classes in school and their level of physical activity at home. The percentage of teens attending daily gym class has stayed relatively steady since 1991; on average, the yearly change in the proportion of students participating was less than 1%. The percentage of ninth- through 12th-graders getting adequate levels of moderate physical activity - exercise such as slow bicycling, fast walking or pushing a lawn mower, which did not make participants break a sweat - also changed very little, from 26.7% in 1999 to 26.5% in 2005, the latest year for which the data was available. Yet obesity rates continued to rise.

http://news.yahoo.com/s/time/20091110/hl_time/08599193677700

[Lance_Boyle]

1. I thought this was long-ago settled. Exercise alone does not make you lose weight.

Dietary modifications are required.

I'd put a huge portion of the blame on soda intake. I'd put the rest of the blame on huge portions.

[paulsby]

10. assuming a constant caloric intake,

exercize WILL make you lose weight.

that's elementary.

if you increase your caloric intake to match (or exceed) that burned by exercise, you won't lose weight.

i also note that "weight" is irrelevant. the issue is fat.

according to BMI, i am very overweight. i'm obese. but my bodyfat percentage is 11%.

any study, article, etc. that refers to WEIGHT is instantly suspect as anti-scientific claptrap.

articles written for laypeople and done by laymedia constantly conflate fat with weight. the BMI (which is a joke) does the same thing

[Lance_Boyle]

15. Well, yes. I was referring to the myth that 30 minutes of cardio 4 or 5 days a week

will melt away the pounds. Not in the absence of lowered intake, it won't.

[paulsby]

16. apart from the melt away thing

assuming a CONSTANT caloric intake, an increase in exercise WILL result in fat loss. how much is another question entirely, but thermodynamics is thermodynamics. if you increase the energy used (which exercise does) and maintain constant energy in , ceteris paribus, you will lose fat.

it is a myth that you have to do BOTH (reduce calories and increase exercise) in order to lose weight

it IS true that doing both GREATLY INCREASES fat loss vs. doing one or the other.

the least effective is lowering calories, but not changing exercise. that usually results in a metabolic slowdown, that can offset the reduced calorie load. CAN, but not necessarily

[flvegan]

2. Publishing a report showing data collected in a "notoriously unreliable" way

seems wasteful to me. Unless they're going to use it as justification to do some actual research.

And don't get me started on school kids attending a daily "gym" class.

[moc]

9. The Youth Risk Behavior Surveillance Survey is "notoriously unreliable"?

Um, okay. Whatever. You do realize that a huge proportion of epidemiological surveillance is done via survey research, including such things as the National Health Interview Survey (NHIS), the National Health and Nutrition Examination Survey (NHANES), and the Behavioral Risk Factors Surveillance Survey (BRFSS), to name but a few. Sure, survey research has its limitations, but it also has its strengths, specifically in terms of statistical power and the ability to look at stratification of risk profiles.

But, sure, make some broad brush dismissal of the methods. It just makes you look silly and uninformed, though.

[flvegan]

13. I'm just quoting the article

And agreeing with Dr. Rankin's take on the study. As for silly and uninformed, surveys that you mentioned utilize the BMI. 'nuff said.

[librechik]

3. hidden ingredients in processed food add pounds

corn syrup and fats--

I'm trying to cook everything from scratch so I know what's in it...

[Junkdrawer]

4. OK. Now you done it....

You just had to attract the Big Agra trolls, didn't you?

[librechik]

7. sorry--I knew when I pushed post that the vultures would land on me

or at least some cheeto lovin DFHs...

[truedelphi]

20. The philosophy that you are stating is the guiding light for a least a

Dozen weight loss programs that people with big bucks pay for and then find work inremoving the lbs.

Hollywood starlets are even told to take it one step beyond the food restrictions - give up the chemicals that are sprayed into our personal care products. Yeah, I know, women have used perfume for thousands of years. However, until one hundred and ten years ago, perfume was mostly flower compounds. Now it is the waste product of the oil distillation chain - so what they cannot put out there for us to put in the cars we drive, they put into personal care products. If they didn't they would have to cart the stuff off to the SUper Fund Sites - a very expensive proposition.

BTW one of the most chemicalized products out there is Fabric Softeners like Downy. Has chloroform and benzene and formaldehyde in it. No wonder babies now have to sleep on their backs with their noses in the air, rather than pressed against the bedding!! The chloroform was
knocking them out and the other chems caused an anaphalactic shock reaction.

[MrMickeysMom]

5. I sense this will become a little hostile soon...

It always seems to be offensive to some.

Very difficult to deny that obesity is by no means impossible to fight and overcome, but some will have a much harder time than others.

That being said, I don't think you have to go far to see what kind of a nation we've become. Just look at the public viewing of JFK's funeral and compare the body types.

Also, our health care system going to be in far deeper waters over the balance of calories in and out.

Let's be civil and seek some helpful conversation and advice... AND support during the process!

[Cali_Democrat]

6. It's because of all the crap they are putting into their bodies

Of course large-scale food businesses benefits tremendously from this.

Whatever boosts profits it a good thing, even if it's at the expense of our health.

This is reality in 'Murka.

[Lex]

8. We consume so many more calories per meal and per day

than we used to. I really think so. David Kessler's book, "The End of Overeating" was an eye-opener.

[iwillalwayswonderwhy]

12. Fat+Sugar+Salt

The trilogy of obese.

[Lochloosa]

11. High Fructose Corn Syrup

[Codeine]

14. NEWSFLASH! Stop the presses! This just in!

Shoveling double handfuls of food down your throat all day long makes you a giant fatty! Who knew?

:eyes:

Coming up after the break, water is wet!

[IDFbunny]

17. It's the sugar and transfats.

[Qutzupalotl]

18. Some tips

Water instead of soda.

Skim milk instead of whole. Try the organic; it's good!

Avoid alcohol, since it slows down your metabolism.

Space out your fats -- don't eat a lot all at once. Put half your meal in a microwaveable container and eat it 3 hours later. Same amount, but you don't send your body into fat storage mode; you speed up its metabolic rate. And it's real food instead of snack food.

Try sugarless gum after a meal to help you skip dessert. Keep it next to your TV chair if you usually eat while watching.

Find veggies you like to snack on to replace some of your junk food. Baby carrots, celery, cauliflower and broccoli have no fat and very few calories. A little peanut butter adds some fat, but many people find it makes veggies more palatable. If you fill up on healthy food first, you will want less junk food.

It's okay to play the reward game if that motivates you.

Find a kind of exercise that's fun so you stick with it.

Don't hate yourself if you fall off your diet.

[Rosa Luxemburg]

19. portion size

and calories

[4_TN_TITANS]

21. I thought the answer would be

all the abstinence only education going on.

[JackRiddler]

22. Sugar junk, HFCS injected into (almost) everything, McDonald's, greasy saltysweet overcooked crap...

What's the big mystery? The decline of the family dinner is probably half the story.

From observation I tend to doubt reports that children are getting the same amount of exercise, however. Gym class attendance doesn't tell much of the story. I have no doubt that a higher proportion of young people who live in my neighborhood were once up and about and active on the streets.