Analysis of study showing how research data can be misinterpreted. The study can be found at URL: http://www.msnbc.msn.com/id/24356209/
By emphasizing relative risks, this study makes the risk of developing heart disease among overweight/obese women seem pretty scary...anywhere from 54% higher to 2.5 times (250%!!) higher. By contrast, when viewed from the perspective of the risk of NOT DEVELOPING heart disease, the results are not as impressive: During the ~11 years of follow up, 98.3% of "normal" BMI women did NOT develop heart disease, 97.1% of "overweight" women did NOT develop heart disease, and 96.4% of "obese" women did NOT develop heart disease. Not exactly headline-grabbing.
The hazard ratios were significantly attenuated when the researchers controlled for hypertension, high cholesterol and diabetes (all higher in the high-BMI categories), suggesting that only a subset of the high-BMI women was at increased risk (and the “healthy overweight/obese” may have little to worry about). Additionally, when the analyses were restricted to only actual heart attacks (nonfatal and fatal), the differences between active women in the different BMI groups were not significant.
This is a great example of how the weight loss industry agenda spins the results. Instead of saying, "exercise makes a major impact on risk factors for heart disease," or "exercise accounts for x% of the outcomes in whether people have heart attacks," they continue to push weight loss, even though it doesn't work and weight cycling increases health risks.
The actual article (which included Joann Manson as an author) emphasized the importance of physical activity more than the MSNBC.com piece.