In layman's terms, a calorie is a unit of measurement of energy you obtain from food. Foods may contain carbohydrates, proteins, fats or a combination of all of them. So, it's obvious that you will derive your calories from carbohydrates, proteins and fats.

Hence, you have to understand these three sources of calories a little better before you formulate your diet plans and begin your weight loss program:

Carbohydrates: Carbohydrates ? a mixture of carbon, hydrogen and oxygen ? are ranked as the top energy source for our bodies. They are generally classified as "refined" or "unrefined" depending on how much they have been processed by food manufacturers.

As far as diets go, carbohydrates are an essential part of any diet because they are nutritious and contain vitamins, minerals, etc.

Proteins: Proteins are a group of organic molecules that are essential in our diet for the growth and repair of tissues. Proteins are the basic building blocks of all living cells.

Our body requires around 22 amino acids (amino acids constitute proteins), 13 of which are manufactured by our body. The remaining 9 come from food and along with them come the calories.

Proteins primarily come from meat and animal products such as beef, lamb, pork, poultry, fish, shellfish, eggs, milk and milk products. Proteins also come from other sources such as grains, beans, fruits and vegetables, but the quantum of proteins from these sources is quite low.

Fats: Fats are the third of the three main classes of foods that impart calories to the body. They are a source of energy and help the body use some vitamins and keep the skin healthy. Fats can be saturated or unsaturated.

Well, by now it is clear that you derive your calories from proteins, carbohydrates and fats. The trick is now to juggle these in such a way that their intake contributes to your diet or weight loss program.

In many weight-training programs, you have to mainly focus on juggling your intake of proteins and carbohydrates, leaving the fats aside and it is important how you plan your meals if you want to establish a healthy diet.

Remember, that calories are fuel or energy for the body and you need to plan your calorie intake if you want to succeed in your weight loss program. Think of yourself as a vehicle that needs fuel to run ? if you don't have fuel, you can't move. If you have too much, that would be worse because it will settle in your body and getting rid of it will be an issue!