Answer: B - When an individual is excreting more nitrogen than being consumed, they are in negative nitrogen balance. This is the oldest and most commonly used method to follow changes in nitrogen (a major component of amino acids, and hence proteins). In short, the amount of nitrogen being consumed is less than the amount being excreted in the urine or fecal matter because it is being conserved. The increase in nitrogen excretion may be caused by fasting (protein breakdown for glycolysis) fever or wasting. Positive nitrogen is typically seen in periods of growth, where protein is being synthesized.