This trial investigated whether an intensive lifestyle intervention to produce weight loss and increased fitness would slow loss of mobility among obese patients with type 2 diabetes. Both weight loss and improved fitness were associated with a decline in the rate of mobility loss. The growing prevalence of type 2 diabetes mellitus is an ominous health threat in the United States 1 , 2 and globally. 3 Surveillance data from the Centers for Disease Control and Prevention cite type 2 diabetes as largely a disease of aging, 4 and its prevalence may escalate as the population gets older. 5 , 6 An insidious consequence of aging in persons with type 2 diabetes is physical disability, 7 particularly the loss of mobility. 8 Reduced mobility puts patients at risk for loss of independence, 9 leads to muscle loss (which compromises glucose storage and clearance), 10 and compromises the quality of life. 11 With increasing age in . . .