Final answer:
Proteins are considered a macronutrient in the human diet because they serve as building blocks for body tissues, provide energy, and have multiple functions in the body.
Step-by-step explanation:
Proteins are considered a macronutrient in the human diet because they are essential for growth and maintenance of the body.
They serve as building blocks for body tissues and are involved in various functions such as muscle contraction, hormone production, and immune response.
Proteins are composed of amino acids and are the most abundant molecules in the body after water.
They provide energy density similar to carbohydrates and play a crucial role in overall nutrition.