Your body needs carbohydrates to supply it with energy. It can also use protein and fat for some of its energy needs, but carbohydrates are the preferred source of energy for your brain. Severely limiting carbohydrates can affect your brain function. For example, a study published in "Appetite" in February 2009 found that low-carb dieters did worse on a memory test than people following a balanced, reduced-calorie diet.
Recommendations vary on what percentage of calories you should get from carbohydrates. MedlinePlus recommends you consume between 40 percent and 60 percent of calories from carbohydrates. The World Health Organization and Food and Agriculture Organization of the United Nations recommend you get at least 50 percent of your calories from carbohydrates, lowering their previously recommended range of 55 percent to 75 percent of calories, in an article published in the "European Journal of Clinical Nutrition" in 2007.
Minimum Recommended Amount
The University of Maryland Medical Center website notes a minimum recommended carbohydrate intake of 100 grams to 150 grams per day. The Institute of Medicine, the organization that sets the recommended dietary allowances for nutrients, recommends consuming at least 130 grams of carbohydrates per day. For most people, this is still below the recommended percentage of calories from carbohydrates. If you consumed 1,200 calories per day, 130 grams of carbohydrates would make up 43 percent of your calories, but it would only be 26 percent of your daily calories if you consumed 2,000 calories per day.
When limiting your carbohydrate consumption, get your carbohydrates from nutrient-rich foods such as whole grains, legumes, fruits and vegetables and reduce the amount of sweets, desserts and refined grains you eat. These recommended foods tend to be low on the glycemic index, meaning they won't cause large spikes in your blood sugar levels and may be less likely to cause weight gain.
Choosing carbohydrates that are high in fiber, and thus low in energy density, or calories per gram, may help you feel feel longer and limit your risk for weight gain. Eating more whole grains, legumes, fruits and vegetables may also lower your risk for heart disease, according to the 2007 "European Journal of Clinical Nutrition" article.