[Metabolic studies during the comparison of a reducing diet with standard nutriton in volunteers]

Using human volunteers the metabolic alterations during standardized nutrition (2,000 kcal/day = 8,400 kJ/day) and during energy-reduced nutrition (1,180 kcal/day = 6,000 kJ/day) with a carbohydrate-containing semiformula diet were investigated. Evaluating the concentrations of blood glucose, serum insulin and serum-free fatty acids it was demonstrated that the nutrition-induced metabolic alterations between the meals (i.e. hyperinsulinemia, low fatty acid concentrations) were not normalized in the group using the standardized diet. In contrast in the group with energy-reduced diet (240 kcal/meal = 1,000 kJ) the concentrations of serum-free fatty acids and of serum insulin reached the fasting values before the next meal. The concentrations of triglycerides and of urea show merely slight reactions following the meals. A rise in concentration of these two parameters is found after the last meal. It is concluded that with the standardized diet the absorption phase following the meals lasts for at least 4 h, whereas the absorption is ended within 2-3 h following the energy-reduced meal. The results of these investigations are interpreted as follows. During a carbohydrate-containing semiformula diet the metabolic mechanisms including the regulations remain unaltered. An effect of the energy reduction is found merely before the next meal. It is assumed that the semiformula diet used does not induce ketosis or glucose tolerance due to a sufficient supply of carbohydrates. With regards to the metabolic effects measured this kind of semiformula diet is judged to be well balanced.