Foods That Build Energy

Your body receives its energy from kilocalories, more commonly referred to as calories. A calorie is defined as the amount of energy needed to raise 1 liter of water 1 degree C. Calories are provided by a class of nutrients called macronutrients, which includes carbohydrates, proteins and fats. Each macronutrient provides a different amount of calories.

Carbohydrates

Carbohydrates provide your body with 4 calories per gram. In addition to calories, carbohydrates also contain glucose, which is a simple sugar that is actually your body's preferred source of energy, according to "Nutrition and You" by Joan Salge Blake. Most of the calories you eat, approximately 45 to 65 percent, should come from carbohydrates. Carbohydrates are mostly found in grains, fruits, vegetables, legumes and nuts. It is important to note that not all carbohydrates provide you with the same nutrition. When choosing carbohydrates you should opt for mostly whole grains, whole fruits and vegetables. Carbohydrates in the form of white sugar and white flour should be limited.

Proteins

Like carbohydrates, proteins also provide your body with 4 calories per gram. Proteins are used for energy when the glucose from carbohydrates is not readily available. In addition to providing you with energy, proteins are also essential for building various enzymes and hormones, maintaining acid-base balance, keeping your immune system healthy and transporting substances throughout your body. Proteins also make up the structural components of all of your cells. Proteins should contribute 10 to 35 percent of your daily calories. The best protein choices include lean meat, fish, poultry, dairy and nuts.

Fats

Fats provide you with the most energy, at 9 calories per gram. Although fats contain the most calories, they are used as a backup source of energy. Fat is converted into energy when you have not eaten carbohydrates for an extended period of time. Your body has an unlimited ability to store fat, but only a limited ability to store carbohydrates. Fats should comprise 20 to 35 percent of your daily calories.

There are different types of fat: saturated, trans and unsaturated. Saturated fats and trans fats, which are found in fried foods, commercially produced items, full-fat dairy and meat, contribute to heart disease and should be limited. Unsaturated fats are the healthy fats that should make up most of your fat intake. Examples of unsaturated fats include avocado, vegetable oils and fish.