– Frequently Asked Questions –
WHY DO WE NEED CARBOHYDRATES?
WHY DO WE NEED PROTEIN?
According to the Dietary Reference Intakes published by the USDA 10% – 35% of calories should come from protein. Most Americans get plenty of protein, and easily meet this need by consuming a balanced diet. We need protein for:
Growth (especially important for children, teens, and pregnant women)
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, legumes, and in smaller quantities in starchy foods and vegetables.
When we eat these types of foods, our body breaks down the protein that they contain into amino acids (the building blocks of proteins). Some amino acids are essential which means that we need to get them from our diet, and others are nonessential which means that our body can make them. 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.
WHY DO WE NEED FAT?
Although fats have received a bad reputation for causing weight gain, some fat is essential for survival. According to the Dietary Reference Intakes published by the USDA 20% – 35% of calories should come from fat. We need this amount of fat 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 and margarines, 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.
A QUICK NOTE ON MICRONUTRIENTS
Although macronutrients are very important they are not the only things that we need for survival. Our bodies also need water and micronutrients. Micronutrients are nutrients that our bodies need in smaller amounts, and include vitamins and minerals. (See the Vitamins and Minerals handout for more information).