The PROVE Trial is a randomized clinical trial that will determine whether a weight loss intervention combined with walking exercise achieves greater improvement or less decline in six-minute walk distance at 12 month follow-up than walking exercise alone in people with PAD and BMI\>25 kg/m2. The intervention uses a Group Mediated Cognitive Behavioral framework, connective mobile technology, remote monitoring by a coach, and a calorie restricted Dietary Approaches to Stop Hypertension (DASH)-derived Optimal Macronutrient Intake Trial for Heart Health (OMNIHeart) diet. 212 participants with PAD and BMI \> 25 kg/m2 will be randomized to one of two groups: weight loss + exercise (WL+EX) vs. exercise alone (EX). Participants will be randomized at Northwestern, Tulane University, and University of Minnesota. Our primary outcome is change in six-minute walk distance at 12-month follow-up. Secondary outcomes are change in 6-minute walk distance at 6-month follow-up and change in exercise adherence, physical activity, patient-reported walking ability (measured by the Walking Impairment Questionnaire (WIQ) distance score), and mobility (measured by the Patient-Reported Outcomes Measurement Information System \[PROMIS\] mobility questionnaire) at 12-month follow-up. Tertiary outcomes are perceived exertional effort (measured by the Borg scale at the end of the 6-minute walk at 12-month follow-up), and diet quality. Exploratory outcomes consist of change in the short physical performance battery (SPPB), the WIQ stair climbing and walking speed scores, and calf muscle biopsy measures at 12-month follow-up. Study investigators will perform calf muscle biopsies in 50 participants to compare changes in mitochondrial biogenesis and activity, capillary density, and inflammation between WL+EX vs. EX.