1. From the Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts;
2. Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts;
3. Department of Psychiatry and Behavioral Science, Stanford Medical School, Stanford, California;
4. Department of Health Policy and Management, Harvard School of Public Health, Boston, Massachusetts;
5. Energy Metabolism Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts; and the
6. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts.