Calories

Definition

Calories are a unit of measurement that indicates the amount of energy provided by food and beverages. They are essential for fueling the body's metabolic processes and physical activities.

5 Must Know Facts For Your Next Test

1. One calorie equals the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.
2. The average adult requires about 2,000 to 2,500 calories per day, but this can vary based on age, gender, and activity level.
3. Macronutrients—carbohydrates, proteins, and fats—contribute different amounts of calories per gram: carbs and proteins provide 4 calories per gram, while fats provide 9 calories per gram.
4. Excess calorie intake can lead to weight gain as unused energy is stored as fat in the body.
5. Caloric needs can change due to factors like illness, pregnancy, or increased physical activity.

Review Questions

• How many calories are in one gram of fat?
• What is the primary function of calories in the human body?
• Why might caloric needs vary between individuals?

Related terms

Macronutrients: Nutrients required in large amounts that provide energy; includes carbohydrates, proteins, and fats.

Metabolism: The chemical processes within organisms that maintain life, including converting food into energy.

Basal Metabolic Rate (BMR): The number of calories required to keep your body functioning at rest.