Objectives: To evaluate the efficacy of a structured very low calorie diet (VLCD) weight reduction/weight maintenance behaviour programme on weight maintenance in obese patients (BMI > or = 30 kg/m2).
Design: Prospective, randomized, controlled intervention trial.
Setting: University out-patient obesity clinic.
Subjects: A total of 114 obese patients from the waiting list were invited to participate in the structured weight reduction/weight maintenance programme lasting for 64 weeks. Sixty patients agreed to participate.
Intervention: All 60 patients were placed on a Cambridge 330 kcal day-1 diet during the first 12 weeks. Fifty-two were subsequently randomized to either a well balanced hypocaloric diet (1600 kcal day-1), of which 220 kcal were provided by two sachets of Cambridge diet (group 1), or the same energy provided by the same principal diet (group 2) during the following 52-week weight maintenance period.
Main outcome measures: During the VLCD period, the mean body weight decreased significantly from 112.4 +/- 19.8 to 91.6 +/- 17.7 kg (P < 0.0001). Seventy-one per cent of the weight loss was fat. During the weight maintenance period the average body weight increased significantly in group 1: 8.0 +/- 8.2 vs. 12.3 +/- 9.7 kg in group 2 (P < 0.0001). After the 64-week treatment period the mean body weight in group 1 was 93.7 +/- 18.1 kg and significantly lower compared to 109.9 +/- 23.8 kg in group 2 (P = 0.008). Compliance was high: 87% completed the VLCD period and 75% completed the whole 64-week treatment programme.
Conclusion: Very low calorie diet as part of the dietary allowance during the weight maintenance programme partly prevents weight regain. This finding can be translated into practical treatment recommendations.