Which nutrient is primarily used for energy and includes sugars and starches?

Carbohydrates are the primary nutrients used by the body for energy and are composed of sugar molecules and larger complexes known as starches. The body's preferred energy source is carbohydrates because they can be quickly converted into glucose, which is used by cells for fuel. Simple carbohydrates, such as sugars, provide immediate energy, while complex carbohydrates, like starches, offer a more sustained energy release.

Proteins are essential for growth, repair, and maintaining body tissues but are not primarily used for energy. Fats, while also a significant source of energy, serve other essential functions such as hormone production and insulation. Nucleic acids, which include DNA and RNA, are crucial for genetic information and do not serve as a primary energy source. Thus, carbohydrates uniquely fulfill the role of being the main energy-providing nutrient in the diet, making them an essential component of a balanced nutrition plan.