The food nutrient with the highest energy value is

1. Analyze the question You are asked which food nutrient releases the most energy per gram. This is about the energy value (calorific value) of nutrients.

2. Explain the concept The energy value of a food class is the amount of energy released when 1 g of it is fully oxidized. The standard values are:

| Nutrient | Energy value | |---|---| | Lipids (fats and oils) | about 39 kJ/g (about 9 kcal/g) | | Carbohydrates | about 17 kJ/g (about 4 kcal/g) | | Proteins | about 17 kJ/g (about 4 kcal/g) | | Minerals | 0 kJ/g (they supply no energy) |

Lipids have a high proportion of carbon-hydrogen bonds and very little oxygen in their molecules. Because of this, they can be oxidized more fully and release more than twice the energy of carbohydrates or proteins.

3. Solve step by step

• A. Protein: about 17 kJ/g, so it is not the highest.
• B. Carbohydrate: about 17 kJ/g, so it is not the highest.
• C. Lipid: about 39 kJ/g, which is the highest.
• D. Minerals: inorganic, so they provide no energy at all.

4. Answer The correct option is C. lipid.

5. Exam tip Remember "Fat = 9, others = 4". Fats give 9 kcal per gram, while carbohydrates and proteins give 4 kcal per gram. If a JAMB question asks about the highest energy value, think of fats and oils. Note that carbohydrates are the body's main and quickest source of energy, but lipids have the highest energy value per gram. JAMB often tests this difference.