Naismith D J, Holdsworth M D
Nutr Metab. 1980;24(1):13-22. doi: 10.1159/000176312.
Adult rats fed a diet containing 14%, by weight, of protein displayed a negative N balance when energy intake was reduced to a value approximating basal metabolism. A positive N balance was induced, however, by raising the protein concentration in the diet, and N retention continued until body fat reserves were almost exhausted. These findings are in conflict with the widely-held view that N equilibrium can be achieved only when the need for energy is satisfied.
给成年大鼠喂食蛋白质含量为14%（按重量计）的日粮，当能量摄入量降至接近基础代谢的值时，其氮平衡呈负值。然而，通过提高日粮中的蛋白质浓度可诱导出正氮平衡，并且氮潴留会持续到体内脂肪储备几乎耗尽。这些发现与广泛持有的观点相矛盾，该观点认为只有在能量需求得到满足时才能实现氮平衡。
