To start this section off, we need to have everyone understand that there are nutrients that you NEED to eat on a regular basis in order for your body to function properly.
These food items are called ESSENTIAL NUTRIENTS ("Glossary")
There are six essential nutrients that your body cannot produce in sufficient quantity for its needs:
Carbohydrates ("Glossary")
Fats ("Glossary")
Proteins ("Glossary")
Vitamins and Minerals (both in "Glossary")
Water
The first three, proteins, fats and carbohydrates, provide you with calories. But they also have many other functions in your body. Vitamins and minerals (notice the picture above is of fruits and vegetables for Vitamins and Mineral... not pills) act as enzymes in your body as well as perform other functions. And water is the last but possibly most important essential nutrient. You have to take these six food items in through your diet in certain amounts on a regular basis or your body will not be able to function at an optimal level.
CALORIES
Carbs, Fats, and Protein are the essential nutrients that provide you with energy. The measure of energy in the food we eat is called a Calorie (with a big C). You can also see Calories listed as Kilocalories, Kcals, or calories (with a small c). All of those mean the same thing to the general population (but to clinicians and researchers they are a little different).
Short video explaining the concept of a Calorie:
To function well during the day, an average adult needs about 2000 Kcals per day. Those Calories come from the food/drink that we consume and each of the different food items provide us with differing amount of calories. Below are the "conversion factors" that can be used to convert grams of a food item into calories for that item. These conversion factors will be useful to know for something that follows this page as well as for the Food Analysis assignment coming up next week.
Protein/Carbohydrates 4 Kcals/gram
If you were to change a gram of protein or a gram of carbohydrates into Calories, you would end up with 4 Calories because they each provide 4 Kcal/gram.
Fat 9 Kcals/gram
Fat provide over twice that amount at 9 Kcal/gram.
Alcohol 7 Kcals/gram
Notice that alcohol was not mentioned as an ESSENTIAL nutrient, but it does provide calories... but people don't realize that alcohol does provide our bodies with calories. When we drink alcohol, it gets into our blood stream (the blood alcohol level) and goes to our liver. We do not and can not store alcohol. Oh and by the way, you don’t pee it out either. I know several of you that are over the age of twenty-one (ahem…..) have noticed that when you drink alcohol, you end up going to the bathroom and pee more frequently with a large volume of fluid. None of the fluid that you are excreting is alcohol. Its just water. The alcohol gets sent to your liver and in there is transformed into fat and stored as fat in your body. So now you know where the term beer belly comes from.