It is unknown whether weight change or physical fitness is associated with chronic kidney disease (CKD) risk among nondiabetic adults with obesity. This was a prospective, longitudinal cohort study of adults with obesity without baseline CKD or diabetes enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA). Linear mixed-effects and multistate models were adjusted for demographics, time-varying covariates including blood pressure, and comorbidities these were used to examine associations of weight change and slow walking pace (<2 miles/h) with (i) rate of annual estimated glomerular filtration rate (eGFR) decline and (ii) incident CKD, defined as eGFRCr-Cys < 60 mL/min/1.73 m2 , and tested for interaction by baseline hypertension status. Among 1208 included MESA participants (median BMI 33.0 kg/m2 [interquartile range 31.2-35.9]), 15% developed CKD. Slow walking pace was associated with eGFR decline (-0.27 mL/min/1.73 m2 /year; 95% CI: -0.42 to -0.12) and CKD risk (adjusted hazard ratio 1.48; 95% CI: 1.08 to 2.01). Weight gain was associated with CKD risk (adjusted hazard ratio 1.34; 95% CI: 1.02 to 1.78 per 5 kg weight gain from baseline). There was no significant interaction by baseline hypertension status. Slow walking pace and weight gain were associated with CKD risk among adults with obesity who did not have diabetes at baseline.