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close this bookProtein-Energy Interactions (International Dietary Energy Consultative Group - IDECG, 1991, 437 pages)
close this folderRespiratory quotients and substrate oxidation rates in the fasted and fed state in chronic energy deficiency
View the document(introductory text...)
View the document1. Respiratory quotients in semi-starvation
View the document2. Respiratory quotients in experimental semi-starvation
View the document3. Respiratory quotients and substrate oxidation rates in chronically energy deficient subjects
View the document4. Substrate oxidation rates during dietary thermogenesis in chronic energy deficiency
View the document5. Effects of refeeding or supplementation on respiratory quotients and substrate oxidation rates of CED subjects
View the documentAcknowledgements
View the documentReferences

2. Respiratory quotients in experimental semi-starvation

Two of the major systematic studies of experimental semi-starvation in man are the "Carnegie experiment", conducted by Benedict and his colleagues in the Carnegie Nutrition Laboratory in 1917-18 (BENEDICT et al., 1919), and the "Minnesota experiment", conducted by Keys and his co-workers in 1945 at the University of Minnesota (KEYS, 1954). The fasting RQs recorded during semi-starvation in the Carnegie experiment were highly variable. The average basal RQ of 0.8, recorded in the volunteers during the control period, was frequently found to be elevated following experimental semi-starvation; in others it remained unchanged, and in a few instances it was below 0.73.

During the semi-starvation phase of the Minnesota study, unfortunately no systematic measurements of RQ were made in the basal, fasted and resting state. Some measurements that were made near the end of the semi-starvation phase showed a mean RQ of 0.84 (range from 0.79 to 0.89). During nutritional rehabilitation, when the food intake and weight gain were highest, the mean basal RQ appeared to be marginally higher at 0.85 (range 0.83 to 0.88) in the few individuals who were studied. However, exercise RQs were determined during the various phases of the Minnesota study. The mean exercise RQs increased throughout the period of starvation and through half the period of rehabilitation and then decreased slightly.