Though fats yield more kilocalories per gram than carbohydrates, they have a lower RQ. Explain.

Energy yield:

• Fats: 9 kcal/g
• Carbohydrates: 4 kcal/g

Respiratory Quotient (RQ):

For carbohydrates:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

RQ = 6CO₂ / 6O₂ = 1

For fats (Tripalmitin):

2(C₅₁H₉₈O₆) + 145O₂ → 102CO₂ + 98H₂O

RQ = 102 / 145 = 0.7

Fats require more oxygen for complete oxidation, resulting in a lower RQ despite higher energy yield.