Although, to our knowledge, this is the first randomized control trial that studied physical function and body com- position changes after a more intensive weight loss inter- vention exclusively in older adults, our findings are consis- tent with those from other populations. Christensen et al. (18) used a wide range in population age (35- to 90-year age range) of obese adults with knee OA. In their 8-week study, the percentage change in the WOMAC index was 35% for the group that lost 11% of their body weight. Their controls also lost significant weight (4.3% of body weight), with only a 15% improvement in WOMAC score. Our WL group experienced a similar level of improvement in WOMAC score ( 33%) as their intensive weight loss group, although their intervention had an increased weight loss (11% vs. 8.5%) and was of shorter duration (8 weeks vs. 6 months). In our previous study examining mild weight loss and exercise, the group that lost only 5.7% of body weight improved their WOMAC physical function score by 24%, whereas the group that lost only 3.7% showed only 11% enhancement in function (10). Furthermore, Jensen et al. (16), using a single-arm study design, found that a 4% change in body weight over 3 months resulted in only a 5% improvement in function. Taken together, these findings indicate that a greater degree of weight loss ( 10%) pro- vides greater benefit to physical function.