How many calories are there in one gram of fat?

Appeared in: SJH Nursing Officer - 2019

Explanation

One gram of fat provides 9 kilocalories (kcal) of energy.
This is more than double the energy provided by carbohydrates or proteins, making fat the most energy-dense macronutrient.
The body uses this energy for various functions, including insulating organs, absorbing fat-soluble vitamins, and as a long-term energy reserve.

Option A: The value of 4 kcal/g is incorrect for fat. It represents the energy content of carbohydrates and proteins.
Option B: 12 kcal/g is an incorrect value and does not correspond to the caloric content of any standard macronutrient.
Option C: 8 kcal/g is incorrect. While it is close to the correct value, it is not the precise standard caloric value for fat. It is closer to the value for alcohol (7 kcal/g).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Caloric value of macronutrients as background academic context rather than a clinical decision trigger.
Understanding the caloric value of macronutrients is fundamental for a nurse when providing dietary education and planning meals for patients with various conditions.
For patients with malnutrition or needing to gain weight (e.g., cancer patients with cachexia), a nurse can recommend incorporating healthy, energy-dense fats.
For patients with obesity, diabetes, or cardiovascular disease, a nurse must educate them on limiting overall fat intake, especially saturated and trans fats, to manage their condition.

How to Approach the Question

This is a factual recall question that tests your knowledge of basic nutrition.
First, identify the core of the question: it asks for the specific number of calories in one gram of fat.
Recall the standard caloric values for the main macronutrients: Carbohydrates (4 kcal/g), Proteins (4 kcal/g), and Fats (9 kcal/g).
Compare the recalled value for fat with the given options.
Select the option that matches the correct value, which is 9.

Concept Tested & Keywords

Q9LFELx57goiqzHJ1SXKFu

E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) pp. 261-263, 282-284

E6 Nutrition Monika Sharma 3e p. 98-100

Practise the full SJH Nursing Officer - 2019

Attempt every question from this paper in a timed mock, then review the full solution for each one.