[Induction of a regimen with a liquid-formula diet does not improve subsequent weight loss]

The liquid-formula diets (LFD) have very restrictive regimens which lead to rapid weight loss. Their use for the induction of weight-reducing therapy is not well known. 20 obese ambulatory patients followed LFD for 2 weeks, followed by 4 weeks of protein-sparing modified fast (PSMF) with natural foods (group A), and 21 subjects followed PSMF for 6 weeks (group B). The LFD supplies 600-650 kcal, 50 g proteins, 100 g carbohydrates and less than 3 g lipids/day. The PSMF delivers 600-1200 kcal, 1.2-1.4 g proteins/kg of standard weight, less than 40 g carbohydrates, and 20 g lipids/day. Patients are checked after 1, 2, 4 and 6 weeks and are asked about their tolerance and cravings by computerized questionnaire. After 4 and 6 weeks, the drop-out rate was significantly higher in group A (30% and 50%) than in group B (0 and 14%) (p less than 0.05). Tolerance is identical in the two groups except for a significant salt craving in the A-patients after 1 and 2 weeks (p less than 0.001). Two subgroups of 8 subjects, comparable in age, weight and percent of standard weight, were individualized in each of groups A and B. As expected, the weight loss was significantly greater in group A after 2 weeks (4.9 +/- 0.5 kg vs 2.8 +/- 0.3 kg, mean +/- SEM) (p less than 0.04), but there was no significant difference after 4 and 6 weeks (total loss 5.7 +/- 1.2 kg vs 5.6 +/- 0.7 kg).(ABSTRACT TRUNCATED AT 250 WORDS)