A client proposes a diet high in processed protein bars, claiming high protein will maximize TEF and therefore burn more calories. Which evaluation is most accurate?

• A. Processed protein bars always produce higher TEF than whole foods because processing concentrates protein and increases thermogenesis proportionally.
• B. Switching to processed bars will cause immediate large increases in daily expenditure that exceed the calories contained in the bars, guaranteeing weight loss.
• C. While protein raises TEF more than fat or carbs, processed protein bars often require less digestive energy than whole-food protein sources and may include added sugars, so whole high-protein foods are a better strategy than relying solely on processed bars.
• D. Protein's TEF is negligible; therefore any emphasis on protein versus processed foods has no logical impact on energy expenditure or weight outcomes.

Answer: (C)