What is the state of nitrogen balance when a person ingests 13 g of food nitrogen and loses 21 g of nitrogen?

- 7 g

Explanation:

Balancing of Nitrogen is a measure that deals with the difference between   nitrogen intake  and nitrgen loss

Nitrogen Balance = Nitrogen intake - Nitrogen loss

Given that

the nitrogen intake = 13 g  and

the  nitrogen loss= 21 g

Therefore nitrogen balance = nitrogen intake - nitrogen loss

= (13 - 21)g = -7 g

Thus, there is a negative nitrogen balance, meaning that the amount of nitrogen excreted from the body is greater than the amount of nitrogen ingested.