Macronutrients
Macronutrients are nutrients that contributes calories or energy. Nutrients are substances needed for growth, metabolism, and for other body functions. Since “macro” means large, macronutrients are nutrients needed in sizable quantities. There are three macronutrients:
Carbohydrate
Fat
Protein
The amount of calories that each one of these macronutrients provides differs :
Carbohydrate provides 4 calories per gram
Protein provides 4 calories per gram
Fat provides 9 calories per gram
What this means is that if you looked at the Nutrition Facts label of a product and it said 15 grams of carbohydrate, 10 grams of protein and 2 grams of fat per serving, if you were to calculate, it will be:
15 x 4 = 60 calories from carbohydrate
10 x 4 = 40 calories from protein
2 x 9 = 18 calories from fat
This food per serving has about 118 calories.
Carbohydrates
Carbohydrates are the macronutrient main source of energy. We need carbohydrate because:
Easily used by the body for energy.
All of the tissues and cells in our body can use glucose for energy.
Needed for the central nervous system, the kidneys, the brain, the muscles (including the heart) to function properly.
Be stored in the muscles and liver and later used for energy.
Important in intestinal health and waste elimination.
Fiber refers to certain types of carbohydrates that our body cannot digest. These carbohydrates goes through the intestinal tract intact and supports the movement of waste out of the body. Diets that are low in fiber have been demonstrated to cause health complications such as constipation and hemorrhoids and to increase the risk for certain types of cancers. On the other hand, diets high in fiber have been shown to decrease risks for heart disease, obesity, and helps lower cholesterol. Foods high in fiber include fruits, vegetables, and whole grain products.
Protein
Both men and women need protein for:
Growth (especially important for children, teens, and pregnant women)
Tissue repair
Immune function
Making essential hormones and enzymes
Energy when carbohydrate is not available
Preserving lean muscle mass
Protein is found in meats, poultry, fish, meat substitutes, cheese, milk, nuts and in smaller quantities in starchy foods and vegetables. Our body breaks down the protein that contains amino acids, which are the building blocks of proteins, when we eat these types of foods, . Some amino acids are essential which means that we need to get them from our diet. Protein that comes from animal sources contains all of the essential amino acids that we need. Plant sources of protein, on the other hand, do not contain all of the essential amino acids.
Fat
Although fats have received a bad reputation for causing weight gain, some fat is essential for survival. We need this macronutrient for:
Normal growth and development
Energy (fat is the most concentrated source of energy)
Absorbing certain vitamins ( like vitamins A, D, E, K, and carotenoids)
Providing cushioning for the organs
Maintaining cell membranes
Providing taste, consistency, and stability to foods
Fat is found in meat, poultry, nuts, milk products, butters, oils, lard, fish, grain products and salad dressings. There are three main types of fat, saturated fat, unsaturated fat, and trans fat. Saturated fat (found in foods like meat, butter, lard, and cream) and trans fat (found in baked goods, snack foods, fried foods, and margarines) have been shown to increase your risk for heart disease. Replacing saturated and trans fat in your diet with unsaturated fat (found in foods like olive oil, avocados, nuts, and canola oil) has been shown decrease the risk of developing heart disease.