Nitrogen Balances during Recovery from Severe Undernutrition

Abstract

The results reported below were obtained on two groups of subjects, Group I in Western Holland in 1945 and Group I1 in the British Zone of Germany in 1946.Among the objects of the Dutch investigation was the determination of the calorieand protein-intake levels which would secure optimum nitrogen retention and rapid increase in weight in severely undernourished patients. The later work in Germany had as one of its objects the determination of the calorie and protein-nitrogen intakes necessary to secure nitrogenous equilibrium in subjects who were considerably wasted. They had lived on diets low in calories and protein over a period of about I year and were in slight negative nitrogen balance when first observed. METHODSThe calorie and nitrogen contents of the daily intakes were estimated from food tables; for foodstuffs of British origin McCance & Widdowson's (1942) tables were used.These were supplemented by values given by the Council of British Societies for Relief Abroad (1945) which contained more up-to-date information on wartime foods and especially on those of American origin.

Dietary protein requirements and recommendations for healthy older adults: a critical narrative review of the scientific evidence

“…Previous studies investigating whole-body protein turnover in the context of mixed macronutrient meal intake demonstrated that anabolic response is not limited by protein synthesis (82)(83)(84) . Deutz and Wolfe (85) advocated that there is no limit to in vivo whole-body protein anabolism when protein is consumed as a part of a mixed macronutrient meal (97,101) . More recently, Park et al (83) showed in healthy older adults (69•3 ± 1•8 years) that there is a higher MPS response following the consumption of a higher protein intake (70 g) compared with moderate (35 g) as part of a mixed macronutrient meal, and a greater whole-body net protein balance in the higher protein intake group due to the suppression of protein breakdown as well as increased protein synthesis (Fig.…”

The Relation of Nitrogen Retention to Nitrogen Intake in Adults With Post-Traumatic Malnutrition

“…In addition, as the protein intake was raised, the calorie intake was usually increased also; such caloric increments may also have tended to give falsely high values for nitrogen storage. The same criticisms may be directed at more recent studies (11)(12)(13)(16)(17)(18)(19)(20)(21) (12) have stated that the amount of nitrogen retention in malnourished men is related more specifically to calorie intake than nitrogen intake. The data used as the basis of the belief in the pre-eminent influence of calories on nitrogen metabolism are presented in Table 5 of Beattie, Herbert, and Bell's paper (12).…”

“…The same criticisms may be directed at more recent studies (11)(12)(13)(16)(17)(18)(19)(20)(21) (12) have stated that the amount of nitrogen retention in malnourished men is related more specifically to calorie intake than nitrogen intake. The data used as the basis of the belief in the pre-eminent influence of calories on nitrogen metabolism are presented in Table 5 of Beattie, Herbert, and Bell's paper (12). However, using these data, correlation of the per cent of absorbed nitrogen retained with the ratio of non-protein calories gives a correlation coefficient of -0.27 (p > 0.1).…”

“…A calorie intake of 35 calories per Kg. per day is considered adequate for patients comparable to those of the present series (12,34).…”

“…For several reasons, however, the relationship between nitrogen intake and nitrogen retention in malnourished adults has not been well defined. In most adult studies, for example, caloric intake has frequently been substantially altered along with variations in nitrogen intake (8)(9)(10)(11)(12)(13). In view of the known effect of non-protein calories on nitrogen metabolism (14) such studies become quite difficult to interpret.…”