Wednesday, July 23, 2014         

 Print   Email   Comment | View 13 Comments   Most Popular   Save   Post   Retweet

Sex to burn calories? Authors expose obesity myths

By Marilynn Marchione

AP Chief Medical Wrier

LAST UPDATED: 03:01 p.m. HST, Jan 30, 2013

Fact or fiction? Sex burns a lot of calories. Snacking or skipping breakfast is bad. School gym classes make a big difference in kids' weight.

All are myths or at least presumptions that may not be true, say researchers who reviewed the science behind some widely held obesity beliefs and found it lacking.

Their report in Thursday's New England Journal of Medicine says dogma and fallacies are detracting from real solutions to the nation's weight problems.

"The evidence is what matters," and many feel-good ideas repeated by well-meaning health experts just don't have it, said the lead author, David Allison, a biostatistician at the University of Alabama at Birmingham.

Independent researchers say the authors have some valid points. But many of the report's authors also have deep financial ties to food, beverage and weight-loss product makers — the disclosures take up half a page of fine print in the journal.

"It raises questions about what the purpose of this paper is" and whether it's aimed at promoting drugs, meal replacement products and bariatric surgery as solutions, said Marion Nestle, a New York University professor of nutrition and food studies.

"The big issues in weight loss are how you change the food environment in order for people to make healthy choices," such as limits on soda sizes and marketing junk food to children, she said. Some of the myths they cite are "straw men" issues, she said.

But some are pretty interesting.

Sex, for instance. Not that people do it to try to lose weight, but claims that it burns 100 to 300 calories are common, Allison said. Yet the only study that scientifically measured the energy output found that sex lasted six minutes on average — "disappointing, isn't it?" — and burned a mere 21 calories, about as much as walking, he said.

That's for a man. The study was done in 1984 and didn't measure the women's experience.

Among the other myths or assumptions the authors cite, based on their review of the most rigorous studies on each topic:

—Small changes in diet or exercise lead to large, long-term weight changes. Fact: The body adapts to changes, so small steps to cut calories don't have the same effect over time, studies suggest. At least one outside expert agrees with the authors that the "small changes" concept is based on an "oversimplified" 3,500-calorie rule, that adding or cutting that many calories alters weight by one pound.

—School gym classes have a big impact on kids' weight. Fact: Classes typically are not long, often or intense enough to make much difference.

—Losing a lot of weight quickly is worse than losing a little slowly over the long term. Fact: Although many dieters regain weight, those who lose a lot to start with often end up at a lower weight than people who drop more modest amounts.

—Snacking leads to weight gain. Fact: No high quality studies support that, the authors say.

—Regularly eating breakfast helps prevent obesity. Fact: Two studies found no effect on weight and one suggested that the effect depended on whether people were used to skipping breakfast or not.

—Setting overly ambitious goals leads to frustration and less weight loss. Fact: Some studies suggest people do better with high goals.

Some things may not have the strongest evidence for preventing obesity but are good for other reasons, such as breastfeeding and eating plenty of fruits and vegetables, the authors write. And exercise helps prevent a host of health problems regardless of whether it helps a person shed weight.

"I agree with most of the points" except the authors' conclusions that meal replacement products and diet drugs work for battling obesity, said Dr. David Ludwig, a prominent obesity research with Boston Children's Hospital who has no industry ties. Most weight-loss drugs sold over the last century had to be recalled because of serious side effects, so "there's much more evidence of failure than success," he said.



Obesity info: http://www.cdc.gov/obesity/data/trends.html

New England Journal: http://www.nejm.org

 Print   Email   Comment | View 13 Comments   Most Popular   Save   Post   Retweet

You must be subscribed to participate in discussions
By participating in online discussions you acknowledge that you have agreed to the TERMS OF SERVICE. An insightful discussion of ideas and viewpoints is encouraged, but comments must be civil and in good taste, with no personal attacks. Because only subscribers are allowed to comment, we have your personal information and are able to contact you. If your comments are inappropriate, you may receive a warning, and if you persist with such comments you may be banned from posting. To report comments that you believe do not follow our guidelines, email commentfeedback@staradvertiser.com.
Leave a comment

Please login to leave a comment.
rayhawaii wrote:
Yet the only study that scientifically measured the energy output found that sex lasted six minutes on average — "disappointing, isn't it?"...... 6 Minutes average??!! Did someone leave off a 0? 21 calories per 6 minutes. 60 / 6 = 10 x 21 = 210 calories on an easy day. Somebody must be missing some exercise, like the 6 min ab machine or something?
on January 30,2013 | 02:55PM
Maneki_Neko wrote:
If you are burning only 21 calories, you're doing it wrong.
on January 30,2013 | 03:07PM
bobbob wrote:
yeah. that's what I'm thinking. I exert WAY more than a walk, and it lasts a lot longer than 6 minutes. They've got to be joking. Maybe 21 calories if you lie on the bottom and flop around a bit.
on January 30,2013 | 05:29PM
Maneki_Neko wrote:
So you know my ex-wife?
on January 30,2013 | 05:59PM
joshislost wrote:
on January 30,2013 | 08:33PM
Anonymous wrote:
and your kids...err i mean my kids
on January 31,2013 | 01:52AM
TLehel wrote:
Wow, even if it's only 6 minutes you can still burn more than 21 calories. Or was this study done on overweight people using minimal effort? I mean, personally I'm sweating profusely afterwards. Then again I get into it.
on January 30,2013 | 03:17PM
blkdrgn wrote:
Does having sex with yourself count?
on January 31,2013 | 04:11AM
blkdrgn wrote:
So how much calories do I burn for lasting one minute, maybe two on a good day?
on January 31,2013 | 04:14AM
palani wrote:
Myth: Soda and other sugary drinks are the cause of obesity in Hawaii.

Truth: Obesity is caused by consuming more calories, from any and all sources, than the number burned off during normal daily activities.

Myth: New taxes and fees on these beverages will reduce obesity in Hawaii.

Truth: No, the new taxes are just another money grab by gluttonous politicians.

on January 31,2013 | 04:44AM
control wrote:
Your point about calories is also out of date and based on myths. All calories are not equal from a metabolic perspective. Studies have shown that native eskimos had diets where 75% of their high calorie diet came from animal fat, yet they were lean and had almost no cardiovasular disease. They also have very little fruit or vegetables in their diets. The fats were primarily omega-3 (the good fats). The kind of calories consumed is critical. Sugary products and all grain products including whole grains are major culprits because your body almost immediately absorbs them into the blood stream. They also have very little nutritional value. They need to be replaced by fruits and vegetables which are nutrient rich and high in fiber.
on January 31,2013 | 07:12AM
saveparadise wrote:
Sex is a good way to burn calories. Doesn't matter how many. Nike says it right....JUST DO IT!
on January 31,2013 | 08:40AM
Kaluu wrote:
Some myths are worth believing. Pau.
on January 31,2013 | 09:15AM
Breaking News