Your body gets energy, which is measured in calories, from the foods you eat. The nutrients that provide calories and yield food energy are carbohydrates, fats and proteins. These nutrients are called macronutrients. A healthy diet includes enough calories from each of the macronutrients to support your energy needs, but not so many calories that you gain unwanted weight.
Carbohydrates are the main source of energy for most people, and each gram provides 4 calories. A balanced diet gets 45 to 65 percent of total calories from carbohydrates, which equates to 225 to 325 grams of carbohydrates per day on a standard 2,000-calorie diet, according to the 2010 Dietary Guidelines from the U.S. Department of Health and Human Services. Sources of carbohydrates include starchy foods like potatoes, beans and grains, and sugars, such as lactose from milk, fructose from fruit or white sugar.
Fat provides the most concentrated source of energy, with 9 calories per gram. Healthy adults should get 20 to 35 percent of total calories from fat, which equates to 44 to 77 grams of fat per day on a 2,000-calorie diet, according to the 2010 Dietary Guidelines from the U.S. Department of Health and Human Services. Unsaturated fats, such as from olives, nuts, canola oil and avocados, are considered healthier than saturated fats, which come from full-fat cheese, fatty meats, butter and coconut oil.
Protein provides 4 calories per gram, and the 2010 Dietary Guidelines from the U.S. Department of Health and Human Services recommend getting 10 to 35 percent of your total calories from protein. This equals approximately 50 to 175 grams on a standard 2,000-calorie diet. Along with providing energy, protein is an essential nutrient for maintaining your lean muscle mass, promoting a strong immune system and allowing chemical reactions in your body to occur. Good sources of protein include meat, poultry, seafood, eggs, dairy products, tofu and beans.
Role of Other Nutrients
When you get carbohydrates, fat and protein from your food, your body needs to metabolize them in order to get energy. Even though vitamins and minerals do not provide energy in the form of calories, many of them are necessary for your body to metabolize carbohydrates, fat and protein. Examples include thiamin, or vitamin B-1; riboflavin, or vitamin B-2; niacin, or vitamin B-3; and magnesium. The best way to meet your needs is to emphasize a wide variety of whole foods in your diet.
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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.