Kilocalories & Diet

Food energy, as well as the energy needs of your body, is measured in kilocalories, or kcalories. Diet, on the other hand, consists of the food and beverages you consume on a daily basis. It goes hand-in-hand that diet determines your kcalorie intake, while your energy needs determine how much you need to eat. If you have ever heard the saying, "You are what you eat," it most certainly is true.

Definition of Kilocalorie

A kcalorie measures the energy in food, or to be more precise, the nutrients. The number of kcalories in a particular food, say a hamburger, can be determined by burning a precise amount of that burger in a device called a "bomb calorimeter," and measuring the amount of heat, or kcalorie it produces. A kcalorie raises the temperature of 1 kg of water, 1 degree Celsius. Just as 1 kg contains 1,000 grams, 1 kcalorie contains 1,000 calories.

Energy Expenditure

Three factors determine the number of kcalories you need: Energy needs when you are awake and resting, which is called your basal metabolic rate; your physical activity level; and the energy you need for digestion and absorption, which is referred to as the thermic effect of food. Your BMR also has to support all the vital processes going on in your body while at rest -- your breathing, your cells are making proteins, your lungs are exchanging oxygen and carbon dioxide, and your stomach is digesting food. All these functions take energy.

Nutrition

To meet your body's need for energy, you eat food, preferably nutritious food that will provide just enough kcalories to meet your needs. There are about 50 nutrients that fall into six classes that you should consume on a regular basis to meet your energy needs. These classes include carbohydrates, fats, protein, vitamins, minerals and water. Energy-yielding nutrients include carbohydrates, which provide 4 kcalories per gram, lipids or fats provide 9 kcalories per gram and protein provides 4 kcalories per gram.

Micronutrients

There are 13 different vitamins in food. Even though vitamins and minerals come from the foods you eat, they are not burned to provide energy, but work with macronutrients to maintain your body processes. Vitamins and minerals are essential, noncaloric micronutrients needed for regulating and maintaining your body. Vitamins are organic nutrients, while minerals are inorganic chemical substances.