 There is a link between treatments of these two diseases as well. There is now solid gold evidence that by treating effectively the obesity of patients with co-occurring OA, the functional status is dramatically ameliorated; the short-term results are equal to that of a joint replacement. The long-term efficacy of a weight loss remains to be shown. OA is definitely one of many diseases in which obesity must be taken seriously into account when planning a correct treatment of patients. This trial is an extension of the former CAROT trial NCT00655941. The participants of this trial are recruited for a prolongation of the dietary intervention consisting of a group therapy with low-energy diet in a randomized, two group each n 75 patients study of maintenance of weight loss by continuing with supplementary either 3 x 5 weeks dietary supplements only or once-daily supplement. The hypothesis is that maintenance of the already induced weight loss is most efficiently ensured by the once-daily program. 