What You Can Change _. And What You Can't - Martin E. Seligman [158]
On the other hand, the gray eminence is the Met Life “ideal weight” table, which in spite of its flaws is well entrenched in the public mind. More modern data supporting the view that even a little overweight is a health risk are found in J. Manson, G. Colditz, M. Stampfer, et al., “A Prospective Study of Obesity and Risk of Coronary Heart Disease in Women,” New England Journal of Medicine 322 (1990): 882–89, which found risk starting at 10 percent overweight among female nurses; and T. Wilcovsky, J. Hyde, J. Anderson, et al., “Obesity and Mortality in the Lipid Research Clinics Program Follow-up Study,” Journal of Clinical Epidemiology 43 (1990): 743–52, which found risk at low levels of overweight with men but not women. See also the National Institutes of Health Consensus Development and Conference Statement “Health Implications of Obesity,” Annals of Internal Medicine 103 (1985): 147–51, which echoes the view that even a little overweight is bad. I find this report overly alarmist, and the tone is considerably moderated by the more recent National Research Council, “Obesity and Eating Disorders,” in National Academy of Sciences, National Research Council, Diet and Health Risk: Implications for Reducing Chronic Disease Risk (Washington, D.C.: National Academy Press, 1989), 563–92.
Nonetheless, there has never been a study that shows anything but a very small statistical increase of coronary risk in the 10 to 30 percent range of overweight.
Underweight: See Keys, “Overweight, Obesity, Coronary Heart Disease;” S. Blair, H. Kohl, R. Paffenbarger, et al., “Physical Fitness and All-Cause Mortality: A Prospective Study of Healthy Men and Women,” Journal of the American Medical Association 262 (1989): 2395–2401; R. Paffenbarger, P. Hyde, A. Wing, and C. C. Hsiesh, “Physical Activity, All-Cause Mortality, and Longevity of College Alumni,” New England Journal of Medicine 314 (1986): 605–13. The mortality risk of the underweight, unlike that of the mild and moderately overweight, is strong, and it is not attributable to smoking or to subclinical disease. See also P. Sorlie, T. Gordon, and W. Kannel, “Body Build and Mortality: The Framingham Study,” Journal of the American Medical Association 243 (1980): 1828–31.
One final caveat: No one has ever done the right kind of study to find out if overweight really causes premature death or poor health. The methodologically right study would randomly assign individuals to different weight levels and see who dies when. It seems likely that for ethical reasons this study will never be done in humans. All of the above studies are therefore distant second-best evidence.
30. Hammond and Garfinkel, “Coronary Heart Disease, Stroke, and Aortic Aneurysm;” P. Hamm, R. Shekelle, and J. Stamler, “Large Fluctuations in Body Weight During Young Adulthood and the Twenty-Five-Year Risk of Coronary Death in Men,” American Journal of Epidemiology 129 (1989): 312–18; L. Lissner, P. Odell, R. D’Agostino, et al., “Variability of Body Weight and Health Outcomes in the Framingham Population,” New England Journal of Medicine 324 (1991): 1839–44; L. Lissner, C. Bengtsson, L. Lapidus, et al., “Body Weight Variability and Mortality in the Gothenburg Prospective Studies of Men and Women,” in P. Bjorntorp and S. Rossner, eds., Obesity in Europe 88 (London: Libbey, 1989), 51–56.
I use the word probably to describe the health risk of dieting. These four studies support it, and their findings do not come out of the blue. A number of smaller-scale studies of humans point to the same health risk for weight cycling, and so does the rat literature. See Garner and Wooley, “Confront the Failure of Behavioral and Dietary Treatments,” for references and a selective review. But I judge the risk “probable,” not “certain,” because two studies fail to find weight variability associated with mortality: L. Lissner, R. Andres, D. Muller, and H. Shimokata, “Body Weight Variability in Men: Metabolic Rate, Health, and Longevity,” International Journal of Obesity 14 (1990): 373–83; and J. Stevens