but because it's weight bearing it can be hard on my joints (arthritis)

Do you suffer from gout? Arthritis can be a medical/dietry issue common amongst obese people, it's causes by a build up of uric acid in the blood resulting from a diet consisting off too much purine rich foods. Purine is mostly found in meat and diary.

Generally to reduce uric acid levels in the blood and crystalasation/soreness that comes with it, you need to avoid processed foods, meat, diary, and fructose, as the kidneys are unable to deal with it.

Being obese also lowers IGF-1 which reduces healing, recovery, and increases inflammation (bad) making soreness worse by increasing uric acid levels in the blood due to an inability to metabolise them effectiveness.

Going through similar experiance with an overweight family member at the moment with kidney problems, they're basically living off vegtables and avoiding startchy foods and meat, their carb sources are limited amounts of whole grain and oats only.