(Getty Images)
(Getty Images)

New research from Stanford shows that physical activity — or lack thereof — may be a bigger driver of the obesity epidemic than diet is.

The researchers looked at national survey results of people’s health habits — including diet and exercise — from 1988 to 2010. The stunner was the increase in people who reported no leisure-time physical activity.

In 1988, 19 percent of women were inactive. By 2010, that number had jumped to 52 percent.

For men, the rate nearly quadrupled, going from 11 to 43 percent in the same time period.

But what didn’t change was the number of calories people consumed. In other words, people were eating about the same but exercising significantly less.

Dr. Uri Ladabaum, a gastroenterologist at Stanford University Medical Center, led the study. He said that the research can only suggest an association between inactivity and increasing obesity, but that people should not decide diet is irrelevant to obesity.

“We would not want to suggest in any way that caloric intake is not important,” Ladabaum said. “But it raises the question of how much of the change in obesity prevalence might be related to physical activity.”

The researchers analyzed results from the National Health and Nutrition Examination Survey, conducted by the Centers for Disease Control. Participants reported their activity over the last month and their diet over the last 24 hours. Ladabaum said the team did not find a difference in total caloric count or breakdown by protein, carbohydrate and fat, over the 22-year study period.

The prevalence of obesity increased from 1988-2010, from 25 to 35 percent of women and from 20 to 35 percent of men.

The data included survey results from more than 17,000 participants between 1988-1994 and about 5,000 people each year from 1995 through 2010.

The study was published in the American Journal of Medicine.

Stanford Study: Inactivity, More Than Diet, Linked to Obesity Increase 9 July,2014Lisa Aliferis

  • Jim Reilley

    If you were in a situation and could only pick one or the other but not both = either healthy diet but no exercise or the reverse; healthy exercise but bad diet?
    My sense is that bad food & lots of exercise while not great goes further than great diet and no exercise.

    • phil

      This reminds me of body builders who go the ‘dirty bulking’ route.

  • Ay.

    I see diet as perhaps a way to change ones habit. But, practicing regularly a sport that a person may like, could help eat enjoyable food and have a certain a body.

    There are many things that could be learned and I doubt that an individual could actually learn it all.

    Nonetheless, when it comes to weight loss the fact it can be linked to obesity or diabetes, make this subject a very important one. Knowing how to lose weight without going through extremely restrictive diets or unbelievable hard workouts may be beneficial.

    I shared some of my thoughts related to this topic on this page: http://9nl.eu/err4

    You may also find there a link to a video that taught me about a phenomenon related to weight loss and genders that I was unaware of.

    What is the point of following an enslaving diet where you have to completely stop enjoying delicious, healthy and lawful food?

  • Clivus

    After the World Cup I am molded to the shape of the couch. Might get up to jake a cup of tea. THAT’S exercise for you.

  • Interesting. Great piece of information. Learned a lot! Thanks for sharing. Anyway, just wanna share, research shows that a professional healthy weight loss exercise for your body type burns 3x more fat and is twice as enjoyable. It also patronizes eating the proper food to have good metabolism for faster fat loss which shows best result.


Lisa Aliferis

Lisa Aliferis is the founding editor of KQED’s State of Health blog. Since 2011, she’s been writing and editing stories for the site. Before taking up blogging, she toiled for many years (more than we can count) producing health stories for television, including Dateline NBC and San Francisco’s CBS affiliate, KPIX-TV. She also wrote up a handy guide to the Affordable Care Act, especially for Californians. Her work has been honored for many awards. Most recently she was a finalist for “Best Topical Reporting” from the Online News Association. You can follow her on Twitter: @laliferis

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