Which bodily function is NOT primarily supported by carbohydrates?

Carbohydrates primarily serve as a key source of energy for the body, particularly for high-intensity activities like muscular work. They play an essential role in fueling exercise and daily physical activities by being converted to glucose, which can be readily used by the muscles.

Body heat regulation is also supported by carbohydrates, as the energy derived from their metabolism is vital in maintaining the body’s thermal homeostasis during physical activity and at rest.

Breathing, while a fundamental process that requires energy, is predominantly driven by the body’s need to supply oxygen to the blood and tissues; this process doesn’t rely solely on carbohydrates for energy. However, the overall energy requirements to sustain breathing can still be met through carbohydrate metabolism.

Cellular regeneration, on the other hand, is a process largely driven by proteins and fats. While carbohydrates can contribute energy, they are not the primary macronutrient involved in the synthesis of new cells or tissues, which predominantly uses amino acids from proteins and fatty acids from fats.

Thus, cellular regeneration does not depend mainly on carbohydrates, which makes it the correct choice in this context.