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Walking can cut obesity gene effect in half
March 14th, 2012
01:30 PM ET

Walking can cut obesity gene effect in half

The millions of people whose genes make them prone to obesity aren't at the mercy of nature. How they choose to spend their free time can make a big difference in their waistline, according to new research presented today at an American Heart Association (AHA) meeting in San Diego.

Watching TV for two hours each day increases the effect of certain obesity-related genes by as much as 25%, the researchers estimate.

If, on the other hand, people with a strong genetic predisposition to obesity spend one hour each day walking briskly or engaging in comparable exercise, they can halve the genes' effect.

"In terms of evolution, this makes sense," says Dr. Roxanne Sukol, a preventive medicine specialist at the Cleveland Clinic, who was not involved in the study. "We didn't evolve to sit still for hours a day."

Health.com: 6 ways to sit less every day

To explore the interaction between behavior and genes, Harvard researchers analyzed data on more than 12,000 men and women participating in two large studies of health professionals.

The researchers measured the participants' genetic risk by identifying how many of the 32 known variants of the so-called obesity geneeach person had. (The gene is officially known as the fat mass and obesity associated, or FTO, gene.)

Roughly half of the general population has some genetic risk for obesity, says lead author Qibin Qi, Ph.D., a research fellow in nutrition at the Harvard School of Public Health, in Boston.

At the same time, Qi and his colleagues looked at how many hours per week each of the participants spent in front of the TV, as well as how much time they devoted to physical activity. Two years into the study, the researchers also recorded the participants' body mass index (BMI), a ratio of height to weight used to measure body fat.

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Each additional obesity-related gene variant was associated with a 0.13-unit increase in BMI, the researchers found. To put it another way, the average person with 7 to 8 variants can expect to have a BMI roughly one unit higher than it would be without the variants. (One BMI unit is equivalent to about six pounds on a 5-foot, 6-inch woman.)

The influence of the gene variants, however, appeared to be strongest in people who watched the most TV. The variants' effect on BMI was about four times greater in people who spent 40 hours or more per week in front of the TV than it was in those who watched an hour per week or less.

"Prolonged TV watching exacerbates the effect of the gene," Qi says.

By the same token, weakening the genes' effect was as simple as switching off the television and going for a brisk walk. The average difference in BMI between a person with the highest genetic obesity risk and a person of identical height with the lowest risk would be cut in half if the high-risk person were to walk for an hour each day, Qi and his colleagues estimate.

Health.com: Walk a little, lose a lot

The main problem with TV watching is that it tends to involve so much sitting, Qi says. As long as they keep moving while they watch, people don't necessarily need to miss their favorite shows.

"Rather than just sitting there, I have a better idea: When they watch, they should exercise," he says. "There's nothing wrong with TV per se, but TV watching may be indicative of a sedentary lifestyle."

Sukol often recommends pedometers to patients who are trying to be more active. The devices enable patients to track their progress by measuring the number of steps they take each day, and they also motivate people to keep walking.

"Human beings are designed to move," Sukol says. "If we're not moving, we put ourselves at risk."

Qi and his colleagues presented their findings today at the AHA's annual meeting on nutrition, physical activity, and metabolism. Unlike the research published in medical journals, the study has not been thoroughly reviewed by other experts in the field.

Copyright Health Magazine 2011

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Filed under: Exercise • Health.com • Obesity

soundoff (26 Responses)
  1. Portland tony

    Genius I say simply Genius. Why hasn't someone thought of this before? Get off of your fat a** and do a little walking! This is an astounding discovery!

    March 14, 2012 at 13:42 | Report abuse | Reply
    • Fred Evil

      Great, now if only we can find a way to lower folks 'Condescending Dickishness' you might have a prayer!

      March 14, 2012 at 16:56 | Report abuse |
  2. chuck

    All it takes is spending 30 mins or so of your lunch time walking. Then spend less time eating lunch by eating less.

    March 14, 2012 at 16:29 | Report abuse | Reply
    • Fred Evil

      Actually, the article says an HOUR a day. Which, with a full-time job, school, and kids, can be harder to find.

      March 14, 2012 at 16:56 | Report abuse |
    • Helen

      I haven't figured out yet how to make the lunchtime walking work for me. Hair gets snow/wind blown or sweaty depending on the weather. And clothes/underwear get rumpled/sweaty. Body odor may bother others working closely. Michigan is too humid to get the lunchtime walk do-able when you work with customers in an office.

      March 15, 2012 at 07:29 | Report abuse |
  3. R A Williams

    This is not good reporting: "Health Magazine". Heads up:

    BMI cannot measure body fat.
    BMI cannot measure body fat.
    BMI cannot measure body fat.

    Got it yet?

    If you want to measure body fat you have to perform (gasp!) a BODY FAT MEASUREMENT. Immersion. Calipers. Electrical. More than one means exists, but comparing height to weight has absolutely nothing to do with body fat. It's like using a ruler to measure temperature.

    The only thing the BMI is good for is comparing couch potatoes to one another and identifying which couch potato is most at risk for lifestyle induced sickness. Add a few pounds of muscle, and everything changes except the equation.

    If you persist in passing off the couch potato index (BMI) as an effective way to measure body fat, please stop calling yourself "Health Magazine".

    March 14, 2012 at 16:32 | Report abuse | Reply
    • muddie35

      100% correct about BMI, it has no distinction between fat and muscle, every profession sports player is obease or overweight according to the BMI Scale.

      March 14, 2012 at 23:27 | Report abuse |
  4. Anna

    The Anti Obesity drug makers and diabetes drug makers take in 10 billion$$$$ every year with no cure!!

    Food Chemicals are the cause of the diabetes and obesity crisis

    The FDA and Drug makers know this and are laughing to the Billionaire$$$ bank

    The food chemicals break the gut(insulin) and this is the cause of the diabetes and obesity crisis

    A filmmaker has been reversing diabetes and Obesity WITHOUT MEDICATIONS in now 10 countries and the drug makers do not promote the story

    just google SPIRIT HAPPY DIET

    March 14, 2012 at 20:06 | Report abuse | Reply
    • medschoolkid

      "food chemicals" do not "break the gut". Type 2 diabetes is caused by an overly fatty diet. The fat builds up in tissues other than fat cells resulting in a resistance to the effects of insulin.

      March 14, 2012 at 23:24 | Report abuse |
    • toadears

      I have no scientific anything to back this up but common sense. Preservatives preserve. Sounds simple, but they must also preserve the bad things in your body a little and slow down the proper digestion of food. How can chemicals be good for us? So I eat natural. Fish, eggs, vegetables, yogurt, fruit...no preservatives allowed. And since I have started on this regime, I feel 90% better. I walk 1 mile a day everyday. My current blood pressure is 120/75 without medication and I am over 60. Monsanto and other companies make a lot of money selling chemicals to food manufacturers in the USA.

      March 15, 2012 at 03:16 | Report abuse |
  5. RunnerGirl70

    Sooo, walking helps cut obesity risk. Was this written by Captain Obvious?

    March 14, 2012 at 20:20 | Report abuse | Reply
  6. Chris

    Okay, pictured is a lovely lady walking under the shady canopy of established trees in her neighborhood, by one of the expensive picket fences she sees along her way. In these articles that suggest walking, no one mentions that for many people, walking is not so genteel. Walking is great, but lets be honest with our imagery.

    And if someone must walk beside a busy roadway, they need to ask their dr about what they might be breathing, or consult air quality reports for their area. They need to consider whether they should take a walking stick along in case of unleashed dogs, or for a general feeling of protection, too. In the summertime, they need to consider whether the walk they plan is safe without a water bottle.

    I'm an introvert who doesn't want to daily run into even the nicest of neighbors who expect me to chat, and there's zero shade along my way! I'm also a caregiver who cannot just walk out my door unless I have backup help. So I do my exercising in my home. I can't afford a treadmill (or the space for it) right now, but workout DVDs are a great thrifty choice for someone like me, and take up zero space when not in use!

    I recommend them to everyone! There's something for everyone to choose from and enjoy.

    March 14, 2012 at 20:31 | Report abuse | Reply
  7. Navin Johnson

    Lost 130 lbs. From 300 to 170 by watching my diet and walking 30-60 minutes for a minimum of 5 days per week.

    March 15, 2012 at 01:30 | Report abuse | Reply
  8. Yes, I Am

    Anyways, that young woman is very special and very precious. I can help her.

    March 15, 2012 at 03:54 | Report abuse | Reply
  9. Gabor47

    There is no such thing as "obesity gene". All this talk about is looking for an excuse why so many people are overweight. Once a wrote a long study about it which obviously wouldn't fit here, but here is the bottom line. Ina twisted sort of way living things work like cars:in order to move, it needs energy. For the car it is gasoline. For humans (living things) it is food. The cars can't pile up extra gasoline (energy) other than it fits into their tanks. Living things can....in form of fat tissue. Therefore, if one swallows more energy (food) than one uses up, the storage (fat) will keep increase.

    My favorite question to my patients (yeah, I am a physician) who claimed that "it is my genes". was: is that gene doesn't exist in Ethiopia or countries where people struggle with famines? If such gene would exist, similar number of fat people should exist there too, but they don't. Every person consumes X amount of energy (expressed by calories) a day and uses up Y amount of calories. If X=Y no weight loss, no weight gain. If X>Y one will gain weight. If X<Y one will lose weight. It is THAT SIMPLE. I am not a diet doctor, but an ob-gyn, who helped patients to lose weight for decades. Honesty and willpower works, excuse searching doesn't. I even wrote a computer program which personalizes activity and food intake, but never marketed it (I am a lousy business person), so only my patients benefited from it. I wish I could make it available to millions, but I can't. Additionally obesity became a business....sort of....so there are some people who's interest is not to help this issue. So, just keep in mind: energy measured in calories. The body needs certain amount of energy a day (which adds up from the basic metabolism, such as heartbeat, respiration, etc.) and physical motion. Foods contain certain amount of energy,also measured in calories. If the latter is more than the former, you will gain weight, if less, you will lose weight.
    The infuriating (for me) part that it is very simple.

    March 15, 2012 at 04:15 | Report abuse | Reply
    • Jo

      Actually those "fat" genes DO exist in Ethiopia and other poor countries. The ones there who can get their hands on enough food DO grow fat very quickly. Our bodies were developed in millions of years of feast-and-famine cycles, and being able to store fat is a good thing if you need to survive hungry months every year. Before the 20th century hardly anyone had enough access to food to get fat, and they had to do physical work in an environment without heating or airco. Our genes and instincts tell us to stuff ourselves with as much fatty, sugary, food we can get – lean times may be ahead. Trouble is that they're not. The only thing that can help is to consciously control our portion size and get exercise.

      March 15, 2012 at 11:01 | Report abuse |
  10. al

    what about walking to a donut shop

    March 15, 2012 at 08:32 | Report abuse | Reply
  11. Geoffrey Hamilton

    This just in, not eating fast food or processed junk food along with eating in moderation is attributed to reducing the other half of the risk. To those parents who can't find the time, have you tried taking your kids to the park? I am working full time, have 2 kids (age 1 and 4), taking 25 cr. hrs at college, and I still have time to work out, or play with my kids at the park. Its called cutting back on the TV intake. If you don't mind, I'm off to play with my kids.

    March 15, 2012 at 10:13 | Report abuse | Reply
    • Spirit

      What do you do if you work 16 hours a day, 6 days a week and hardly ever see your children because by the time you come home, it's 8 in the morning, they're at school, and you have work in six hours so you spend those free hours catching up on sleep?

      April 4, 2012 at 14:33 | Report abuse |
  12. TrekDesk

    The body also triggers development of particular cells (e.g. muscle or fat cells) based on your activity levels. If you sit in an office all day and at home in front of the TV set it triggers T-Cells to produce more fat cells. You have heard "you are what you eat" but many do not know "You Are What You Do". Keep moving as much as possible during the day and avoid the chairs until the very late evening as much as possible. That will have a tremendous impact on your your life and health.

    March 15, 2012 at 12:18 | Report abuse | Reply
  13. Momof6

    Metabolism and genes do seem to play a big role. I have 6 daughters. Of them, I have 1, who is overweight. She eats the same as the rest of us. She is a dancer and has dance classes 4 days a week lasting 1.5 to 2 hrs each time, plus extra practices, and choreographing her own dances at home. She is much more active than most of her sisters, who not only are not at all overweight, but are naturally slim to the point of being at the low end of charts for height/weight. They do not dance, do not do sports, do not work out regularly. We eat healthy and I run marathons, so am health conscious and exercise regularly. My husband, their father, also exercises regularly and is not overweight. It is a difficult situation to deal with. Weight management is not always as easy as those who post on these sites would like to make it seem.

    March 15, 2012 at 13:45 | Report abuse | Reply
  14. Jason

    It seems simple, but what you are saying is completely true. The problem with this issue is that the health and fitness industry are out to make money, not help people get results. Billions are spent on fitness, yet the obesity rate keeps rising. There is an obvious disconnect there.

    That is what inspired me to start a non-profit organization that provides a complete program...exercise, nutrition, personalized support from people who really care...100% for free. We take money out of the equation and make it about helping people. It is called LiveFit Revolution.

    We are getting incredible results. Hundreds of people losing thousands of pounds. We are making in impact by supporting people in doing things just like this article suggests...walking and being more active. We are fighting to get the word out there: if you want to lose weight and need help, we are here for you.

    Thanks again for the article. Jason – livefitrevolution.org

    March 15, 2012 at 14:06 | Report abuse | Reply
  15. jake3_14

    "By the same token, weakening the genes' effect was as simple as switching off the television and going for a brisk walk. The average difference in BMI between a person with the highest genetic obesity risk and a person of identical height with the lowest risk would be cut in half if the high-risk person were to walk for an hour each day, Qi and his colleagues estimate. "

    This is a classic bit of pseudo-science. There is no science to jump to the conclusion that 1 hour walk does this. Qi and his group did not test the actual time watching TV or sleeping or just sitting or another other form of inactivity. Or what is "brisk" or why not make it 4 hours or 5 minutes. Or by what mechanism this reversal is happening. What about the TV watcher that runs a hour a day?

    Although 12,000 sound like a lot of people, if you start dividing the group by age, gender, starting BMI, and # of variants, you are really looking at very small groups of people which may or may not be statistically significant. Even the conclusion on BMI gain per variant is somewhat suspect.

    This is yet another article taking a bit of science ie variants on a "fat" gene and projecting a common but non-tested belief that minimal exercise will make you better.

    March 15, 2012 at 21:14 | Report abuse | Reply
  16. john

    you want to know the cure for obesity? Well all you have to do is stop eating like a pig and exercise like a normal person.

    March 15, 2012 at 21:37 | Report abuse | Reply
    • jake3_14

      This comment is filled with so much ignorance, it's hard to know where to begin to respond. "Eat less, move more" has been the mainstream recommendation for dealing with the obesity epidemic since it began. It doesn't work, and not because people are too weak-willed or lazy to follow the advice. It doesn't work because it's a misapplication of classical thermodynamics. Those laws apply to closed systems of inert objects, where there are no self-regulating feedback systems that are sensitive to the environment. Human beings are subject to the rules of biology, which depend on these types of feedback systems. Your body will slow down its metabolism if food is scarce and rev it up when food is plentiful. Studies in rats show that the body will hang on to fat even at the expense of muscle and internal organ tissue; fat is that important to surviving.

      Further there are *zero* clinical studies that show a causal connection between exercise alone and weight loss. Taubes addresses this directly in "Why We Get Fat."

      March 15, 2012 at 22:18 | Report abuse |
  17. Randall Lewis

    Great article. Now if you think TV is bad what about smart phones? The average person uses their smart phone for 2.7 hours a day to socialize on social networks. Walking is a great exercise and if done correctly can help your cardiovascular system tremendously. If you can't walk due to physical ailments then try swimming. Swimming is a low-impact workout and is extremely good at helping to lose weight.

    Weight loss + motivation = weight loss motivation.

    Let's get in shape so we can live healthier lives.....www.weightlossmotivation2012.com

    April 10, 2012 at 00:26 | Report abuse | Reply

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