Which concise definition best describes protein-energy malnutrition (PEM)?

An exclusively protein-deficiency disease caused by inadequate intake of branched-chain amino acids while calories are adequate, leading only to muscle cramps without growth impairment.

A spectrum of disorders resulting from inadequate intake of protein and energy, leading to impaired growth, tissue loss, and organ dysfunction.

A genetically determined metabolic disorder in which the body cannot metabolize dietary proteins, unrelated to dietary caloric intake.

A condition characterized by excess protein intake relative to carbohydrates, producing kidney overload and chronic dehydration but not associated with caloric insufficiency.