Journal of Aging Research [34, 35]. These ﬁndings are particularly salient because both muscular strength and power, particularly in the weight- bearing lower limb muscle groups [36], have been strongly associated with habitual and maximal gait velocities, as well as other measures of physical function (i.e., chair stand time) in community-dwelling, mobility-limited, older adults [37]. Collectively, these works suggest that a low muscle/body mass ratio directly impairs movement among obese, older adults. Musculoskeletal pain, often in the form of osteoarthritis, is also associated with obesity and directly impacts the ability of older persons to remain mobile. Complaints of pain in the leg joints related to osteoarthritis, particularly in the knee, are common in older adults. In fact, self-reported joint pain is often cited as the main factor aﬀecting mobility in older adults [38]. Noteworthy, mobility limitations due to joint pain are compounded by obesity [39]. This is signiﬁcant considering that most adults with knee osteoarthritis have a body mass in the overweight or obese range (body mass index (BMI) ≥ 25 kg/m2) [40]. Additionally, the Women’s Health and Aging Study found that obesity was a distinct risk factor for substantially increasing the risk of mobility disability among individuals with chronic pain [41]. In line with this, obesity has been identiﬁed as the main preventable risk factor for the onset and progression of osteoarthritis and the associated pain by some experts [42]. Importantly, individuals with chronic pain often modify and lessen their activity by walking and engaging in less physically de- manding activities. As such, the age-related degeneration and the associated pain, which is compounded with obesity, can lead to signiﬁcant reductions in activity. In addition to the direct and immediate eﬀects that excess body weight has on movement, obesity may have an overlooked, long-term impact on mobility function through the development of comorbid disease conditions. The devel- opment of such conditions, including cardiovascular disease and diabetes, may lead to mobility impairments beyond those observed during obesity alone. In fact, accumulating evidence indicates that older adults with diabetes, obese or not, experience more severe losses of muscle mass and strength than those who are not diabetic [43]. Although the mechanisms that cause this accelerated loss of mobility among older adults who have diabetes are unclear, much of the decline may be due to exacerbated changes in body com- position typically observed in advanced age and/or obesity. Collectively, studies to date indicate that excessive body weight, metabolic disease, and sarcopenia all contribute to declines in mobility function (see Figures 1 and 2) [1]. Sig- niﬁcantly, comorbidities associated with metabolic disease and sarcopenia are prevalent in older adults, and the health consequences associated with each condition are compounded by obesity (Figure 1). Each of these conditions is directly associated with lifestyle habits. As previously discussed, excessive caloric intake and a sedentary lifestyle promote weight gain and contribute to the progression of age-related sarcopenia and declines in mobility function. Over time, these changes can accelerate the development of mobility impairments and disability (Figure 2). Although aging is the primary risk factor for both of these con- ditions, healthy dietary and physical activity habits have Obesity Comorbidities Aging (Relative) sarcopenia Strength Gait speed Mobility impairment Community participation Loss of independence Risk of nursing home admission Mortality 3 Figure 1: Conceptual model illustrating how obesity potentiates age-related declines in gait speed that might lead to mobility impairment, loss of independence, and mortality. n o i t c n u f y t i l i b o M Never obese Obese at young age Age Disease Onset of mobility impairment Obese at middle age Figure 2: Theoretical illustration demonstrating the relative impact of obesity on mobility function within the context of aging and disease onset. demonstrated eﬃcacy in attenuating the progression of these conditions. In the next section, we will highlight important research ﬁndings over the past few decades demonstrating the beneﬁcial eﬀects of nutritional and exercise interventions on mobility function in obese, older adults. 4. Diet and Exercise Interventions to Improve Mobility Function in Obese Older Adults A current challenge for clinicians and researchers working with overweight, older adults is to design lifestyle-based in- terventions that can produce signiﬁcant weight loss while minimizing the loss of fat-free mass. Concerns about weight