What are calories? Commonly referred to as 'calories', a calorie is a unit of energy, used by all living organisms to grow, maintain healthy body tissue and perform physical activity. Food gives our body energy from its macronutrients – carbohydrates, proteins, and fats – that it converts into glucose for metabolism. Calories are the sum of all energy used by your body … [Read more...] about Calories vs Kcal: What is the Difference Between?