This is a substudy to a randomised trial investigating the effect of liraglutide on body weight and pain in overweight or obese patients with knee osteoarthritis (NCT02905864). In the parent trial, patients will be subjected to an 8-week diet intervention phase including a low-calorie diet and dietetic counseling, after which patients will be randomised to receive either liraglutide 3 mg or liraglutide 3 mg placebo as an add-on to dietetic guidance on re-introducing regular foods and a focus on continued motivation to engage in a healthy lifestyle.