Eating the RDA amount of protein results in which nitrogen status?

• A. Nitrogen balanced
• B. Positive nitrogen balance
• C. Negative nitrogen balance
• D. Nitrogen imbalance

Answer: (A)

Nitrogen balance is the key idea here: your body’s nitrogen comes from dietary protein, and it’s lost mainly in urine as urea, plus some from sweat and feces. When the nitrogen you take in matches what you lose, you’re in nitrogen balance — no net gain or loss of body protein.

The RDA for protein is set to keep healthy adults in that balanced state, roughly 0.8 g of protein per kilogram of body weight per day. So eating the RDA amount provides just enough protein to replace the nitrogen lost, maintaining equilibrium. If you consumed more protein than you lose, you’d have a positive nitrogen balance (as in growth or muscle building). If you consumed less, or if losses were higher due to illness or stress, you’d have a negative nitrogen balance. Nitrogen imbalance isn’t a normal steady state in healthy adults.

So, eating the RDA amount of protein results in nitrogen balanced.