Final answer:
Growing children are in positive, not negative, nitrogen balance because they require more nitrogen for tissue growth. Negative nitrogen balance would result from inadequate protein intake and could lead to health issues including stunted growth.
Step-by-step explanation:
The statement that growing children are in negative nitrogen balance because they need more protein for adding blood, bone, and muscle cells is false. Growing children are generally in a positive nitrogen balance, which indicates that the intake of nitrogen, primarily from protein consumption, exceeds the amount of nitrogen excreted. This is necessary for the growth and development of new tissues. A negative nitrogen balance occurs when nitrogen intake is less than nitrogen output, which can happen in cases of inadequate protein intake, illness, or when the body is in a state of stress or catabolism. This condition would impede growth in children and is not the normal state during healthy development. Children in the growth phase indeed need an adequate supply of dietary proteins to support their increased requirements for amino acids, which are necessary for synthesizing new cells and tissues. Insufficient protein during growth can lead to conditions like kwashiorkor and can result in serious health consequences, including stunted growth and impaired cognitive development.