The definition of energy is the capacity to do work. Regular energy is needed to keep the human body functioning properly. Energy, which is measured in calories, comes from the foods we eat, although not all food groups provide the same amount of energy and some do not provide much energy at all.
Carbohydrates should generally make up around half of one's total daily caloric intake; thus, they are considered a major source of energy in the daily diet. Good sources of carbohydrates include whole grain breads and cereals, popcorn, whole grain pasta and granola. Fresh fruits and vegetables, honey, jams, jellies and syrups also contain some carbohydrates. Carbohydrates are broken down into sugar inside the body; therefore, they impact blood sugar levels easier than other food groups do. Combining carbohydrates with protein, for example, having crackers with cheese, will help lessen their impact on blood sugar levels. Carbohydrates provide four kilocalories per gram.
Protein provides the same amount of energy per kilogram as carbohydrates. Sources of protein include lean meats such as chicken, turkey and fish, nuts, eggs, Greek yogurt, beans and cheese. Protein helps satisfy hunger longer, rebuilds muscle and maintains blood sugar levels. Most people consume enough protein without extra effort; however, some people may need to increase protein intake. Pregnant women, high-level athletes and vegetarians are those who sometimes need to eat more protein.
Fats, which provide more energy than protein and carbohydrates, have nine kilocalories per gram. Although energy rich, fats should be consumed in moderation because excess fat is stored as adipose tissue and can lead to conditions such as atherosclerosis, high cholesterol and diabetes. Fats can be classified as either "good" or "bad" fats. Bad sources of fats include foods such as cookies, cakes, candy, fatty red meats and deep-fried foods. These foods are considered high in fat but low in other nutrients, making them less than optimal dietary choices. Good sources of fats include nuts, avocados, low-fat meats and cheeses and healthy oils such as olive and canola.
Alcohol provides seven kilocalories per gram, placing it directly between fat and protein and carbs. Although it does provide energy, it contains no other nutrients and should be consumed in moderation. Alcohol consumption is not appropriate for everyone. Alcoholic beverages, especially mixed drinks such as margaritas and mojitos, are often higher in sugar and calories, making them an unhealthy addition to one's diet, particularly if consumed in excess.
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