Why Do We Need Carbohydrates In Our Diet?

Carbohydrates is one of the three macronutrients found in food, along with protein and fat. Each macronutrient has a different role, but all of them provide energy or calories to help your body go through your daily activities. Carbohydrates are actually made up of starches, sugars and fibers and can be found in grains, such as breakfast cereals, rice, pasta, granola bars, baked goods, crackers, legumes, fruits, milk, yogurt and any food that contains sugar.

Dietary Guidelines

The "2010 Dietary Guidelines for Americans" recommends that about half of your daily calories, or between 45 percent to 65 percent to be exact, be provided by carbohydrates. This amount of carbohydrates corresponds to between 225 g and 325 g of total carbohydrates, of which 25 g to 38 g should be fiber, based on a 2,000-calorie diet. The carbohydrate recommendation can be met by following MyPyramid, which promotes the daily consumption of 5 to 8 oz. of grains, 1.5 to 2 cups of fruits, 3 cups of dairy and up to 265 calories' worth of sugar or processed foods, based on a 2,000-calorie diet.

Carbohydrates Role

While protein serves as a building block to repair and maintain the integrity of your cells, tissues and organs and fat is involved in the production of hormones and is a constituent of the membrane of each of your cells, the main role of carbohydrates is to provide energy. Some of your body cells, especially in your brain and your red blood cells, prefer to run on glucose, a type of sugar that can be obtained through the consumption of carbohydrates. When you exercise, your muscles can also use glucose as their main source of fuel.

Low-Carbohydrate Diets

Many low-carb eating plans recommend restricting your carbohydrate intake below 20 percent of your calories, which corresponds to 100 g or less of total carbohydrates a day. Although it is generally advised that the bulk of your calories be provided by carbohydrates, "the lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed," according to the "Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids," published by the Institute of Medicine in 2005. The glucose that is needed by the brain and red blood cells can be manufactured from protein if you reduce your carbohydrate intake. Moreover, if you lower your carbohydrate intake, your body adjusts and switches to using fat as its main source of fuel, providing ketones which can also be used by your brain and various organs as a source of energy. Although carbohydrates provide energy, it is not an essential nutrient if your diet includes adequate amounts of protein and fat.

Finding The Right Amount of Carbs for You

Although the recommended carbohydrate intake corresponds to 225 g to 325 g a day, some people benefit from lowering their carbohydrate intake, whether it is to promote fat loss, better manage blood sugar levels or improve blood cholesterol levels. The best way to find out what works best for you is to change your carbohydrate intake, by either increasing or decreasing it, until you find the level that helps you feel energized while helping you reach your weight loss and health goals.