Yes, calories from different foods are metabolized differently. The source of the calories will effect how they are metabolized.
yes they are
Calories are not a form of weight. It could be different amounts for different foods no-matter what the weight is.
About 10% of the total calories intake.
There are so many types of foods out there, that it really depends on what the food is.
False!
There is no such thing as "common foods". Foods are specific sometimes ot certain regions or areas, and there are so many foods out there. Please be more specific in your question, so WikiAnswers can provide you with the best possible answer.
All foods have calories.
Generally, yes. But your body will process the foods differently. 2000 calories of cake is not that much cake. A few slices will do it with some cakes. 2000 calories of apples is a lot. That's like 20+ apples
Use the equation E=mc2 . where c is the speed of light and multiply that by how many million milligrams you've got. Different foods have different calories not because they have different milligrams or weights, but because they are different foods altogether. A milligram of chocolate would have more calories than a milligram of water because you get more energy from eating a milligram of chocolate than drinking a milligram of water.
foods free of calories
all foods have calories in, some just have more than others!
You can do anything from how much weight it gains eating different foods to if it acts differently in different kinds of water!