[A low-energy protein diet and complete fasting in obese patients. Effect on energy metabolism]

The authors investigated 38 obese patients with a BMI above 35. The patients were divided into four groups. The first three groups were on a strict reducing diet, which differed as to the energy values (1.38 MJ to 2.75 MJ) and the amount of protein (5.58 g N to 17.91 g N) per 24 hours. The fourth group fasted. In the course of 16 days metabolic balances were made and the energy output at rest was assessed by indirect calorimetry. In all groups the body weight declined markedly on average by 8.2 to 10.5 kg. The energy consumption at rest declined only during the complete fast. The fasting patients were in a negative nitrogen balance. The nitrogen balance was positive in the patients who were given 11.2 g N and 17.91 g N/24 hours. In all groups the fat utilization increased and the sugar utilization declined. The protein catabolism declined markedly only in the fasting patients. It may be summarized that the low-energy protein diet is, as compared with the fast, a more physiological way to achieve weight reduction, in particular because despite weight reduction a positive nitrogen balance is achieved.