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V Young

Publications and source records attributed to V Young.

53 records · Page 3Linked to original sources
PubMed1981

The mechanisms of nitrogen sparing in fasting supplemented by protein and carbohydrate.

Estimated rates of total body protein synthesis breakdown, and amino nitrogen flux were determined in five obese females using [15N]glycine. The subjects were fed a baseline diet of 1.5 g protein/kg ideal BW and 1602 +/- 146 Cal total for at least 3 days, followed by 3 weeks where the sole caloric intake was a mixed diet of 0.8 g meat protein and 0.7 g carbohydrate/kg ideal BW and approximately 437 +/- 44 Cal. Amino nitrogen flux, total body protein synthesis, and breakdown values were 289 +/- 56, 198 +/- 37, and 202 +/- 47 g protein/day (187 +/- 24, 129 +/- 19, and 131 +/- 21 g protein/g creatinine) initially and fell significantly (P less than 0.01) to 192 +/- 30 (P less than 0.005), 138 +/- 27 (P less than 0.01), and 146 +/- 25 (P less than 0.01) g protein/day [125 +/- 13 (P less than 0.001), 90 +/- 14 (P less than 0.005), and 95 +/- 11 (P less than 0.005) g protein/g creatinine] by the final 60 h of the third week. Nitrogen balance remained significantly negative (P less than 0.01) during each week of the mixed diet and overall (--3.3 +/- 0.9 g N/day; P less than 0.01). Thus, total body protein synthesis and the net balance between synthesis and catabolism are not maintained with this diet.

Adult↗
PubMed1977

Effect of a protein-sparing diet and brief fast on nitrogen metabolism in mildly obese subjects.

Five young, mildly obese females consumed a formula diet providing total calories at 1.2 X basal energy expenditure and egg white protein, 1.5 gm./kg. ideal body weight (IBW), for 1 week (period 1). During period 2, lasting 3 weeks, a protein-sparing modified fast (PSMF) consisted of similar amounts of egg white without nonprotein calories followed by a 1-week total fast (period 3). In the final period (4), a PSMF with the use of meat protein, 1.5 gm./kg. IBW, alone was given for 1 week. Nitrogen balance (Nbal) measurements were made in all periods, and periods 2, 3, and 4 were compared with period 1. No significant difference existed between period 1 and period 2, although Nbal improved weekly during period 2. Nitrogen excretion in period 3 was similar to that found after 3 weeks of total fasting and was significantly negative, whereas positive balances occurred in period 4 with both periods being significantly different from period 1. Thus nitrogen equilibrium in the PSMF can be achieved with the use of protein free from fat, confirming earlier experience with meat protein. The metabolic adaption which occurs during toal fasting and results in reduced nitrogen loss develops in the course of PSMF. After a deficit in lean body mass is produced, net protein anabolism can be achieved by a PSMF despite insufficinet dietary energy.

Adult↗