According to the July 11, 2013 issue of The New England Journal of Medicine, the Look AHEAD trial has been canceled on the “basis of a futility analysis” after 9.6 years of follow-up. It was designed to study whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among overweight or obese patients with Type 2 diabetes. Short of interning people in exercise camps, it is hard to imagine a more intensive intervention.
The 5,145 participants were randomly assigned to either a control group or an intensive lifestyle intervention group. The control group received the usual information about behavioral strategies for adopting standard recommendations about how to eat right and exercise.
There are four key patterns of results that emerge. First, the lagged effect of physical activity is almost always larger than the current effect. This suggests that current risk factors, not only obesity but also high blood pressure and heart rate, take years to develop, which underscores the importance of consistent physical activity to ward off heart disease. Second, we find that in general physical activity reduces risk factors for heart disease even after controlling, to some extent, for unobservable confounding influences. Third, not only recreational but work-related physical activity appears to protect against heart disease. Finally, there is evidence of a dose-response relationship such that higher levels of recreational exercise and other physical activity have a greater protective effect. Our estimates of the contemporaneous and durable effects suggest that the observed declines in high levels of recreational exercise and other physical activity can potentially account for between 12-30% of the increase in obesity, hypertension, diabetes, and heart disease observed over the sample period, ceteris paribus.
Source: NBER Working Paper.
Heresy at Health Affairs:
Virtually unheard of thirty years ago, workplace wellness is now embedded in large self-insured companies. These firms pay their workers an average of $460/year to participate in worksite wellness programs. Further, wellness is deeply enough engrained in the public policy consciousness to have earned a prominent place in the Affordable Care Act, which allows large employers to tie a significant percentage of health spending to employee health behavior and provides direct subsidies for small businesses to undertake these workplace wellness programs.
Yet the implausible, disproven, and often mathematically impossible claims of success underlying the “get well quick” programs promoted by the wellness industry raise many questions about the wisdom of these decisions and policies.
So why are we doing this? I proposed an answer in Priceless: wellness programs attract employees who are already healthy and repel those who aren’t.
Research on the [indigenous Tsimane of northern Bolivia] led to the finding in 2009 that cardiovascular disease is probably an ill of modern societies. Studies of the group also provided the most conclusive data supporting the idea that high levels of physical activity drastically reduce the risk of diabetes, obesity and hypertension.
There have been 42 studies with results published, and at least 33 more are under way. “This is the most productive research site in anthropology today,” Ray Hames, an anthropologist at the University of Nebraska-Lincoln, said.
Jean Friedman-Rudovsky in the NYT.