Americans spend a lot of time worrying about obesity. Should we really be focusing on fitness?
That’s the conclusion of a new meta-study, which concludes that, rather than excess pounds, it may be a lack of exercise that shortens one's life. It finds “fit individuals who are overweight or obese are not automatically at higher risk” of premature death.
“Much more attention should be given to promoting physical activity and cardiorespiratory fitness as a means to reduce risk for disease and death,” writes a research team led by Vaughn Barry of Middle Tennessee State University. Its study is published in the journal Progress in Cardiovascular Diseases.
"Compared to normal weight-fit individuals, unfit individuals had twice the risk of mortality, regardless of BMI. Overweight and obese-fit individuals had similar mortality risks as normal weight-fit individuals."
Barry and his colleagues decided to examine the evidence regarding the “fitness-fatness hypothesis, which suggests a higher level of cardiorespiratory fitness will substantially reduce the adverse effects of obesity on morbidity and mortality, making obesity a much less important factor for health than is generally believed.”
After sifting through the literature, they narrowed their focus to 10 studies that measured both fitness and body-mass index (BMI). While the precise methodologies of the studies differed, fitness was measured via exercise trials, while BMI was used to categorize participants as normal, overweight, or obese.
The studies they examined were, for the most part, quite large: Two had more than 20,000 participants, while three others had more than 10,000 participants. Adding them all together, far more men than women took part; six of the studies were all-male, compared to only two that were all-female.
Participants were followed up with between seven and 16 years after the initial data was taken. Researchers determined how many had died in the interim, and compared their initial BMI and fitness levels with that of the participants who remained alive.
The key result: “Compared to normal weight-fit individuals, unfit individuals had twice the risk of mortality, regardless of BMI. Overweight and obese-fit individuals had similar mortality risks as normal weight-fit individuals.”
So a sedentary lifestyle, not excess weight, seems to be the killer.
“These findings are promising for all individuals, including those unable to lose weight or maintain weight loss,” the researchers conclude, “as all can experience significant health benefits by developing or maintaining a moderate level of cardiorespiratory fitness by participating regularly in physical activity (such as) brisk walking or biking.”
This level could be reached, they add, with “150 minutes of moderate-intensity physical activity per week,” a regimen that “should not be intimidating, and is achievable by most unfit individuals.”
So rather than instructing their patients to lose weight—a goal many of them have undoubtedly tried and failed to accomplish—perhaps physicians and other health professionals should place more emphasis on physical fitness.
Even if you can’t resist dessert, there’s no reason you can’t take a brisk walk after dinner. This research suggests that simple choice could literally mean the difference between life and death.