Two snack formulations have identical calorie counts but different macronutrient distributions. From a metabolic perspective, which statement is the best evaluation of how the body treats these calories?

• A. High-protein formulations always yield more net usable calories in metabolism because protein digestion is completely lossless and increases energy availability.
• B. Although total energy is the same, macronutrient composition affects metabolic pathways, satiety, and storage (e.g., high-fat snacks provide more energy per gram and may be stored differently), so identical calories can have different physiological outcomes.
• C. Calories are calories in metabolism: the body treats all macronutrient-derived calories identically with no differences in storage, satiety, or metabolic cost of processing.
• D. From a metabolic viewpoint, carbohydrate calories are preferentially stored as long-term adipose tissue immediately after consumption whereas fat calories are rapidly excreted unused by the body.

Answer: (B)