Which of the following is a key function of fat in our diet?

Fat plays a vital role in our diet primarily as a source of energy. It provides the most concentrated form of energy among macronutrients, yielding about 9 calories per gram compared to 4 calories per gram provided by carbohydrates and proteins. The body utilizes this energy for various physiological functions, including physical activity and maintaining body temperature.

In addition to being an energy source, fats are essential for the absorption of certain fat-soluble vitamins (A, D, E, and K) and play a critical role in hormone production and cellular structure. The inclusion of healthy fats in the diet is important for overall health, as they contribute to satiety and help to regulate metabolism. Given these roles, the significance of fat as an energy source is foundational to understanding its importance in human nutrition.