Energy Metabolism, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA. Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA. Biostatistics and Data Management Unit, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. Metabolic Research Unit, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. Nutritional Epidemiology, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA, USA. Cardiovascular Nutrition, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. Department of Epidemiology, School of Public Health, Indiana University, Bloomington, IN, USA.