A calorie is an energy unit. It is found in food and it is what keeps our body alive. Calories can come from proteins, carbs or lipids. When someone wants to lose weight efficiently, counting calories is the best. It is very simple.

First of all, you have to determine how many calories you need to lose weight. A daily deficit of 500 calories is needed to lose one pound per week. But, it is important to not go under 1200 calories (women) and 1500 calories (men) because it is the minimum that your body needs to survive. If you wonder: "How many calories do I need then?", let me tell you that there are plenty of free calculators on the Internet that will give you the amount of calories you need to consume everyday depending on your activities. So, depending on your metabolism and your level of activities, these calculators will show you how many calories a day you need.

In average, 2000 calories is the number of calories burned per day by people. But, if you are sedentary or, on the contrary, very active, you may burn less or more than that.

Finally, as for calorie counting, lots of websites shows how many calories there are in different types of food. For examples, calories in chicken can differ depending on the way it was cooked. Grilled chicken breast (3 oz.) has around 211 calories, on the other hand, fried chicken breast has 307 calories, 115 of which come from fat.