Calories as we know are actually 1,000 calories or 1 Kcal, but we commonly refer 1 Kcal as a calorie.
Calories come from three sources.
Carbohydrates, fat, and protein. Fat 9 Carbohydrates 4 Protein 4 As you can see, fat produces more calories compared to carbohydrates and proteins. Each person has a requirement of calories in a day that they must consume. The R.D.A bases it standards on a person with a need of 2,000 calories a day. Factors that can change this number are your age, body size, metabolism, pregnacy, and daily activities.