The atmosphere of doom, blame and guilt has grown pretty thick around the subject of obesity these days, in case you hadn’t noticed. In documentaries, public health warnings and, increasingly, in their doctors’ offices, obese Americans hear a drumbeat of bad news and reproach. Among the most alarming of the warnings: Obesity will almost certainly cut short these Americans’ lives.
A new study, just published in the Journal of the American Board of Family Medicine, says that may not be exactly true. The study, which tracked 50,994 Americans between the ages of 19 and 90 for a total of six years, suggests that obesity itself may not be a harbinger of impending death: Rather, hypertension and type 2 diabetes -- admittedly common fellow travelers to obesity -- make people more likely to die in the near term.
Put another way: At any given age, an obese person who does not have type 2 diabetes or high blood pressure is no more likely to die sometime in the next six years than is a person of the same age who is of normal weight.
The study deepens the body of emerging research that suggests that body mass index alone is not a terribly good predictor of an individual’s health status -- and that, in some cases, carrying a little extra weight appears to confer some benefits.
In fact, the type 2 diabetes patient who is of normal weight -- with a BMI between 20 and 25 -- was more likely to die of any cause during the six-year study period than was a type 2 diabetes patient who was overweight or -- yes -- obese, the study found. And the super-thin patient with type 2 diabetes? The underweight (those with BMIs below 20) were far more likely to die during the six-year study period than their obese peers, the study found.
Overall, severely obese Americans -- those with a BMI above 30 -- were more likely than those who ranged anywhere between normal weight and mild obesity (up to BMI of 29.9) to die during the six year period. But if you just took the “healthy severely obese” -- those who have not developed high blood pressure or type 2 diabetes -- and compared them with those of “normal healthy weight,” members in each group stood a roughly equal chance of surviving the next six years.
Important? Well, yes.
The authors of the study, physicians from the University of California Davis’ department of family and community medicine, acknowledge it may seem they’re splitting hairs here. After all, obesity undeniably makes type 2 diabetes and elevated blood pressure much more likely.
But people of normal, “healthy” weight -- indeed even underweight people -- get those diseases too. And once you know that it’s those diseases -- and not obesity per se -- that predict an untimely death, a physician can accurately assess which of his or her patients is at greater mortality risk and should be most aggressively treated. And public health authorities can focus scarce public resources on battling “Public Enemy Number One” -- not, in fact, obesity, but diabetes and high blood pressure, even (in fact especially) when they occur in thin people.
Certainly, preventing weight gain or losing weight is one way to combat diabetes and high blood pressure. But other strategies clearly help keep diabetes at bay, like routine intensive exercise, tighter control of high cholesterol or, for pregnant women, limiting weight gain. Early recognition of high blood pressure can quickly get a patient on medications and making lifestyle changes that can bring it under control, which in turn lowers his or her risk of developing diabetes.
“The study findings should not be construed to mean that overweight and obesity no longer represent major threats to individual and public health,” wrote the authors. But on the basis of this new information, a physician might look at a mildly obese senior without hypertension or diabetes as a “hardy survivor” unlikely to prolong his life by losing weight, says study co-author Dr. Anthony Jerant. And the same physician might not be so quick to give a slim patient with type 2 diabetes a pass on the “get out there and exercise” lecture.
“It adds a little more nuance and counteracts some of the knee-jerk reactions” of doctors, public health authorities and regular Americans, Jerant says. “Obese patients sort of get stigmatized,” Jerant adds -- they’re costing taxpayers money, they’re responsible for a projected decline in life expectancy, their food intake brands them as foolhardy and undisciplined. This study, says Jerant, may refocus health-promotion efforts in more fruitful ways.