[Thermogenesis in humans after varying meal time frequency]

To a group of 8 healthy persons a slightly hypocaloric diet with protein (13% of energy), carbohydrates (46% of energy) and fat (41% of energy) was given as one meal or as five meals in a change-over trial. Each person was 2 weeks on each regimen. Under the conditions of slight undernutrition and neutral temperature the balances of nitrogen, carbon and energy were assessed in 7-day collection periods, and according to 48-hour measurements of gaseous exchange (carbon-nitrogen balance method) by the procedures of indirect calorimetry. Changes of body weight were statistically not significant. At isocaloric supply of metabolizable energy with exactly the same foods in different meal frequencies no differences were found in the retention of carbon and energy. Urinary nitrogen excretion was slightly greater with a single daily meal, indicating influences on protein metabolism. The protein-derived energy was compensated by a decrease in the fat oxidation. The heat production calculated by indirect calorimetry was not significantly different with either meal frequency. Water, sodium and potassium balances were not different. The plasma concentrations of cholesterol and uric acid were not influenced by meal frequency, glucose and triglycerides showed typical behaviour depending on the time interval to the last meal. The results demonstrate that the meal frequency did not influence the energy balance.