Which statement best defines a zero energy balance?

• A. Calories expended exceed calories consumed, producing a persistent negative balance and predictable weight loss over the short term.
• B. An energy-sparing state where metabolic adaptation causes intake to appear equal to expenditure despite ongoing tissue catabolism.
• C. Calories consumed equal calories expended, leading to weight maintenance.
• D. A small positive energy balance over weeks that results in gradual fat gain if maintained because intake slightly exceeds expenditure.

Answer: (C)