What class of nutrients are consumed in large quantities and provide calories?

The correct answer is macronutrients. Macronutrients are the nutrients that the body requires in larger amounts to provide energy (calories) and support physiological functions. This category includes carbohydrates, proteins, and fats. Each of these macronutrients plays a distinct role in energy provision and overall health.

Carbohydrates are the body's primary source of energy, while proteins are essential for growth, repair, and maintenance of tissues; they are also important for the production of enzymes and hormones. Fats not only provide a concentrated source of energy but are also vital for absorbing fat-soluble vitamins and supporting cell membrane integrity.

In contrast, micronutrients, such as vitamins and minerals, are needed in much smaller quantities and do not provide energy on their own, but they are crucial for various biochemical processes in the body. Enzymes, while vital for facilitating biochemical reactions, are not classified as nutrients and do not provide calories either. Understanding the importance and roles of macronutrients is fundamental in nutrition and fitness, especially when it comes to designing effective dietary plans.