What food constituent is primarily responsible for the high content of energy in cheese?

The food constituent primarily responsible for the high energy content in cheese is fat.

Here's why:

* Fat is the most energy-dense macronutrient: Fat provides about 9 calories per gram, compared to carbohydrates and protein, which provide 4 calories per gram.

* Cheese is naturally high in fat: Cheese is made from milk, which is naturally rich in fat. The fat content of cheese varies depending on the type of cheese and the production process, but it can range from around 20% to over 40%.

While cheese also contains protein and some carbohydrates, the high fat content is the main contributor to its high energy density.