The authors of the study, published Monday in the Archives of Internal Medicine, concluded that physicians' efforts to improve their obese patients' health by promoting lifestyle change might do better to embrace "a more realistic expectation": a modest reduction of patients' waist circumference and the prevention of further weight gain.
That discouraging picture comes just three months after Medicare, the nation's healthcare safety net for seniors, announced it would reimburse primary care physicians for providing obese patients "intensive behavioral therapy" to lose weight and improve their health. Increasingly, physicians, who have been told they can be a powerful prod to healthy behavior change in their patients, are devising ways to play that role: they are incorporating nutritional and weight-loss counselors into their practices and honing their own roles as motivational agents for increased exercise and weight loss.
But many studies, including the current one, suggest that expectations for these efforts are impossibly high. For patients who already have entered obese territory, even interventions far more intensive than those that most physicians are equipped to provide will fall short of hopes -- if those hopes focus on bringing a patient's body-mass index (BMI) under 30. Weight loss -- for men and women -- is hard enough, and maintaining weight loss an even tougher challenge.
But does that mean that "lifestyle interventions" cannot improve patients' health? Sometimes that depends on how you define and measure improvements -- and BMI may not always be the best bellwether.
A growing body of research -- including the current study -- is focusing on measures of fatness that may be more amenable to lifestyle changes, and which might reflect meaningful improvements in a patient's health prospects. One of those focuses on fat deposits that girdle the waist and visceral organs, where they can play havoc on metabolic function.
Easily measured with a tape measure, for instance, the circumference of a patient's waist appears to be a better measure of risk for developing type 2 diabetes than is BMI. For men, a waist circumference greater than 40 inches, and for women, greater than 35 inches, has been linked consistently to higher risk of cardiovascular disease, type 2 diabetes and early mortality.
In this study and others, researchers have found that waist circumference tends to respond most to changes in exercise: with more physical activity, fat is less likely to cling to the middle, where it's most dangerous. While that may not translate directly into pounds lost, it may well bring health benefits that will drive down patients' disease risk.
Waist circumference as a measure of health may not be the big kahuna that body-mass index is -- yet. But it's making inroads. A quick search of the nation's clinical trials shows that some 1,631 studies using human subjects make use of BMI as a measure. Waist circumference, a measure of health barely seen in clinical trials a decade ago, is now used in some 571 today.