Carbohydrates are one of the main types of nutrients. They are the most important source of energy for your body. Your digestive system changes carbohydrates into glucose (blood sugar). Your body uses this sugar for energy for your cells, tissues and organs. It stores any extra sugar in your liver and muscles for when it is needed.
Carbohydrates are called simple or complex, depending on their chemical structure. Simple carbohydrates include sugars found naturally in foods such as fruits, vegetables, milk, and milk products. They also include sugars added during food processing and refining. Complex carbohydrates include whole grain breads and cereals, starchy vegetables and legumes. Many of the complex carbohydrates are good sources of fiber.
Common food sources of naturally occurring carbohydrates include:
- As a source of energy - The main function of carbohydrate is to supply energy for the body processes. A greater part of the energy in the diet (more than 50-80%) is supplied by carbohydrates. Some of the carbohydrates are immediately utilized by the tissues and the remaining is stored as glycogen in the liver and muscles and some are stored as adipose tissues for future energy needs.
- Protein-sparing action - Carbohydrates are mainly utilized by the body of fulfilling the major part of the energy needs, thus sparing protein for tissue building and repairing. The first physiological demand of the body is the need for energy, which must be satisfied before the nutrients are used for other functions. So, this function of carbohydrates to spare protein for its primary purpose of body building and repair of tissues is an important one.
- Essential for Fat Oxidation - Carbohydrate is essential for oxidation of fats. Recent studies have shown that oxalacetic acid, a breakdown product of carbohydrate is essential for the oxidation of acetate, which is the breakdown product of fats.
- Role in gastro-intestinal function - Carbohydrates play an important role in the gastro-intestinal functions of mammals. Lactose promotes the growth of certain desirable bacteria in the small intestine which brings about the synthesis of certain B-complex Vitamins. Lactose also enhances the absorption of calcium. Cellulose provides fibre and bulk which helps in the stimulation of the peristaltic movements of the gastrointestinal tract.
Risk of High Carb Diet
Consuming too many carbohydrates or choosing the wrong sources can have negative health consequences.
- Heart Disease - A diet rich in high-glycemic index carbohydrates may increase the risk of coronary heart disease in women. The high-glycemic carbohydrates included bread, sugar, jam, pizza and rice.
- Diabetes - Studies found that high-carbohydrate diets increased women's risk for developing type-2 diabetes. Women who consumed about 337 grams of carbohydrates per day were 28 percent more likely to develop diabetes than the women who ate about 263 grams per day.
- Pancreatic Cancer- A study by the National Cancer Institute found that high glycemic index carbohydrates may increase the risk of developing pancreatic cancer. In the study, overweight, sedentary women with high glycemic loads and high fructose intake were at the greatest risk for pancreatic cancer. Normal weight, active women with the same type of diet were at a high risk as well.
- Breast Cancer- According to a 2004 study in Mexico, women whose daily carbohydrate intake represented 57 percent or more of their total calories were more than twice as likely to develop breast cancer. There are several types of carbohydrate compounds, and the study found that sucrose and fructose demonstrated the strongest association with breast cancer risk. Sucrose and fructose are found in sweeteners and fruit.
- If deficient in carbohydrates, the body will utilize protein and fats for energy. Ketosis occurs in the absence of carbohydrates when glycogen (glucose stores in the liver) is depleted. Regularly consuming fruits, which contain carbohydrates and starchy vegetables, will prevent ketosis from occurring.
- Fibre is an essential component in our diet for cancer prevention and healthy digestion. Without some whole grains, one would need to consume a large amount of fruits, vegetables and legumes to meet.
Daily fibre requirements