We compared the importance of rate of initial weight loss for long term outcome in obese patients and the efficacy of two different dietary weight maintenance programmes. An initial weight loss of 12.6 kg was achieved either by eight weeks low energy diet (2 MJ/day) (n = 21) or 17 weeks conventional hypocaloric, high protein diet (5 MJ/day) (n = 22) both supported by an anorectic compound (ephedrine 20 mg and caffeine 200 mg thrice daily). Weight loss rate had no effect on long-term weight maintenance. Randomisation to one year weight maintenance of either an ad lib, low fat, high carbohydrate diet or a fixed energy diet (< 8 MJ/day), both supported by reinforcement sessions 2-3 times monthly, resulted in a maintenance of 13.2 of initial 13.5 kg weight loss in the ad lib group versus 9.7 of 13.8 kg in the fixed energy intake group. At follow-up two years after the initial weight loss, 65% of the ad lib group and only 40% of the fixed energy intake group had maintained a weight loss of > 5 kg.