Carbohydrates are the main source of energy for the body; they include starches, sugars and dietary fiber. Starches are naturally found in some plant products, such as potatoes, rice, wheat and legumes. They are converted to energy by the body after consumption.
Sugars are found in natural whole foods, such as fructose in fresh fruit and lactose in milk. The sugar in fruits and milk are generally low, and excessive intake of it from fruits and milk are not comment. Dietary fiberis essential in a healthy diet; it helps lower cholesterol, and reduces the risk of constipation and colon cancer.
Some carbohydrates are healthier than others. Carbohydrate of whole food, such as brown rice and fresh fruit are healthier as maximal amounts of naturally occurring vitamins, minerals, fiber, and other health promoting substances retained.
In contrast, refined carbohydrates have lost most of the nutrients, especially fiber, during processing and thus should be limited from the diet. Sugars, such as table sugar and syrup, are also added into the foods and beverages during food processing to enhance flavor.
These added sugars provide the same amount of calories as natural carbohydrates but nutrient density is much lower so they should also be limited.
|Natural Carbohydrates||Refined Carbohydrates||Added Sugars|
|Whole-wheat bread||White bread||Cakes, doughnuts|
|Fresh whole fruit||Fruit juice||Canned fruit with heavy syrup|
All types of carbohydrates provide 4 calories in each gram yet the nutrient content varies among them. Natural, unrefined carbohydrates should be the major source of energy contributing to the largest portion of daily intake.
Eating too few natural carbohydrates is common, causing inadequate intake of dietary fiber, which is associated with heart disease, constipation and colon cancer.
Excessive intake of carbohydrates, especially added sugars and refined carbohydrates, can cause weight gain.
Approximately 55% of daily energy intake should be from carbohydrate sources, mainly natural carbohydrates. For example, an adult who needs 2000 kcal per day should consume about 275 g carbohydrates.
Carbohydrate Rich Foods
- A bowl of Taiwanese beef noodle ~ 84
- A bowl of rice noodle with fish balls ~ 60
- Three small cha siu buns ~ 57
- Two pieces of salmon sushi ~ 19
- A brown rice ball stuffed with shredded chicken and mushroom ~ 83
- A small bowl of mashed potato ~ 76
(Source: Chinese University of Hong Kong Food Composition Database)SourcesNatural carbohydrates (healthier): whole grains (e.g. whole wheat breads, oatmeal, red rice and brown rice), root vegetables (e.g. potatoes and taro), milk and milk products, and fresh fruit.