Protein is one of the basic components of food and makes all life possible. Amino acids are the building blocks of proteins. All of the antibodies and enzymes, and many of the hormones in the body are proteins. They provide for the transport of nutrients, oxygen and waste throughout the body. They provide the structure and contracting capability of muscles. They also provide collagen to connective tissues of the body and to the tissues of the skin, hair and nails.
Fatty acids are individual isomers of what we more commonly call “fats”. There are potentially hundreds of different fatty acids, but just a few dozen that are commonly found in the foods we eat. Nutritionists commonly classify dietary fat as either saturated, monounsaturated, or polyunsaturated, based on the number of double bonds that exist in the fat’s molecular structure. For each of these three classes, there exists a large number of different chemical variations or “isomers”. These include the EFA’s or Essential Fatty Acids. Fats are required to produce and build new cells. They are a source of energy and are critical in the transmission of nerve impulses and brain function and development. They are also involved in the synthesis of other essential molecules such as hormones.
Carbohydrates are the chief source of energy for all bodily functions and muscular exertion. They are necessary for the digestion and assimilation of other foods. They help regulate protein and fat metabolism, and fats require carbohydrates to be broken down in the liver. They also provide some of the structural components necessary for the growth and repair of tissues. (macronutrients description source: bodybuilding.com forum, username: Diab0lic)
For fat loss, muscle building and maintaining weight you should aim to consume the appropriate amount of macronutrients. Protein, fat and carbohydrates are three key elements that the body needs in order to function properly. To calculate your macronutrient requirements, the formula below is a good starting point and may be perfect for you. However, each person is different, for example if your day job calls for intense strenuous activity such as a construction worker, you may need more carbohydrates than someone who works a desk job to accommodate for the excessive amount of energy expended. Therefore calculate your carbohydrate intake first as a priority, then calculate your protein and fat out of your remaining calories. Be sure to experiment until you figure out what works best for you, trial and error is key in finding the best results.
1 gram of protein per pound of body weight
.4 (minimum) grams of fat per pound of body weight
Fill in the rest of your calories with carbohydrates
4 calories per gram of protein
9 calories per gram of fat
4 calories per gram of carbohydrates
For example: we will use a 175lb man with a 2300 calorie diet, his macronutrients would be as follows:
Protein: 1g x 175lbs = 175g (175g x 4 = 700 calories)
Fat: .4g x 175lbs = 70 (70g x 9 = 630 calories)
Carbohydrates: Take your 970 remaining calories of your 2300 calorie diet, divide it by 4 and your carbohydrate consumption should be 242.5 grams.