The effect of short-term deprivatioa (10 days) on plasma cholesterol, triglyceride, phospholipids, free fatty acids, high density lipoprotein cholesterol (HDLC) and low density lipoprotein cholesterol (LDLC) were investigated in seven medical students (Urban adults) aged between 21 and 24 years and eight Village Adults aged between 30 and 40 years. There were significant falls in all the plasma lipids except free fatty acids and the plasma triglycerides of the village adults. Plasma proteins in all subjects were reduced while the fall in albumin was significant only for the urban adults. Positive correlation of Mbody fat with plasma lipids was only significant for HDLC in the urban adults and triglycerides for the village adults. There was no correlation between plasma proteins and lipids except with HDLC for village adults. Tbe village adults however, were observed to show a less stressful effect on plasma lipids than the Urban adults though they reacted to the short-term deprivation more or less in the same manner.
1. The present study was carried out to estimate precisely, via the nitrogen balance technique, requirement or Nigerians (earlier estimated via the obligatory N method) using graded levels intake.
2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study Graded levels of protein (0-3, 0-45, 0-6 and 0-75 g/kg body-weight per d) derived from foods similar to be consumed by the subjects.
3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of intake (0-75 g) and the second group starting with the lowest level of protein intake (0 3 g). N intake during each of the eleven experimental periods was maintained at 0-2 MJ/kg per d. After adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked for five consecutive days for N determination.
4. Mean N balance during consumption of the four protein levels (0-30, 0-43, 0-6 and 0-75 g/kg) t (SD 8.07), — 9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analyses daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight). allowances for individual variations to cover 97.5 % or the population adjusted this value to 0-75g body-weight. Net protein utilization for the diet at maintenance level was estimated at 57.5.
1. A continuous 40 d metabolic nitrogen balance study was conducted on twelve young men age years to evaluate the adequacy of a previously determined safe level of protein intake.
2. Subjects were fed on diets which they were habitually accustomed to and which provided a pro 0.75 g protein (N x 6.25)/kg body-weight per d as the safe level and an energy intake level of 0.2 f weight per d. N balances, including an estimate for integumental losses as well as certain biochemical were determined for the last 5 d of two consecutive 20 d diet periods.
3. Only two of the twelve subjects were observed to be in negative N balance during the final 5 < period. N balance was generally positive at 8-24 (SD 8.61) mg N/kg body-weight, thus confirming of 0.75 g protein/kg body-weight per d as a safe level of protein intake in the majority of the subject
Twelve healthy female subjects aged < between 21 and 32 years were fed graded levels of protein inform of the habitual diet to which they were accustomed, in order to differentiate effects of this dietary component on urinary and plasma uric acid excretion. Urinary uric acid increased significantly with increase in the level of protein intake. The average daily uric-acid excretion at the four levels of protein tested were 297.7 ± 44.5, 282.9 ± 45.0. 304.6 ± 31.8 and 331.4 ±26.5 mg/day for 15.7. 21.4, 27.4 and 32.7g protein/day respectively. Thus urinary uric acid increased linearly by 2.14 mg/g protein. There is, therefore, a positive correlation between the amount of protein Vitamin and urinary uric acid excretion (r - '0.34) However, plasma uric acid did not change with Increase In dietary protein. This was attributed to a possible increase in renal clearance.
SThe effect of varying energy intakes on nitrogen balance was investigated in thirteen young women aged between 21 and 32 years. The subjects were fed a previously determined minimum requirement of protein (0.47 g/kg) at two levels of dietary energy, high energy intake at 48.4±3.70 kcal/kg bodyweight and low energy intake of 33.8±2.86 kcal/kg bodyweight (about 20% above and below the estimated energy requirement based on their energy expenditure); Nitrogen balance was determined from the nitrogen in food, urine, feces and sweat. Nitrogen balance was -8.6±5.44 mgN/kg with the low energy intake and increased to +10.82±6.35 mgN/kg with the high energy intake. Regression analysis, showed that all subjects maintained zero nitrogen balance with an average energy intake of 40±0.94 kcal/kg/day. Variation in energy intake also altered the net protein utilization of the habitual diet in till subjects by 1.0 to 3.5 units/kcal per kg body weight. Energy requirement was estimated on lite basis of constant body weight and the nitrogen balance. Body weight was maintained constant at an energy intake of 40.8±4.21 kcal/kg body weight
Thirteen normal healthy female adults aged 21 to 32 years participated in an energy balance study while they consumed their habitual diet at two energy levels (33.8±2.96 and 48.4±3.7 kcal/kg/day) and a protein level of 0.47g protein/kg/day. The physical activity of the subjects was closely monitored and kept fairly constant. Energy balance calculated from the gross energy intake, energy excreted (urine, feces and sweat) and expenditure on activity was affected considerably by the level of the gross energy intake. Energy balances were -6.3512.57 and +7.31±2.24 kcal/kg/day for the low and high energy intakes respectively. Energy balance improved by a factor of 0.9410.1 for every kcal/kg rise in gross energy intake. Mean energy requirement to achieve energy balance in all the subjects was estimated at 40.311.4 kcal/kg body weight.