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Nutrient Series: Carbohydrates
There are those who say we eat too many carbohydrates, and those who claim we don’t eat enough. Most nutritionists will tell you that we need carbohydrates, but we eat too many of the wrong kinds. So how do we know what’s right?

Carbohydrates are the body’s energy powerhouses. They provide the fastest fuel with the least amount of metabolic stress. A carbohydrate molecule is made up of carbon, hydrogen and oxygen, and carries the water-soluble vitamins B and C.

Carbohydrates are found as simple sugars and complex chains (starches and fiber). The sugars are known as monosaccharides and disaccharides. Monosaccharides are the most available and are commonly known as galactose, a milk sugar component, and the fruit sugars glucose and fructose. It’s the glucose molecule that provides fuel to the cells.

Disaccharides are a combination of two monosaccharides bonded together. Sucrose, for example, is glucose and fructose – that is, table sugar. Maltose is two glucose molecules and lactose, otherwise known as milk sugar, is composed of glucose and galactose. These bonds are easy to break and make it very easy for your body to get its energy.

Starches and dietary fibers, known as complex carbohydrates, are simply chains of more than two sugar molecules. It is the complex carbohydrate that absorbs water, transports vitamins and contains essential micronutrients.

Carbohydrate digestion is so fast that some of it starts right in the mouth and immediately enters the blood in the form of glucose. The simple sugars would be examples of this rapid digestion. Digestion of complex carbohydrates takes longer while enzymes work to break down the larger molecule chains. When you hear about the “glycemic index,” it refers to the amount of time a particular food takes to raise blood glucose levels.

So, back to the question of which is healthier: avoiding carbohydrates or increasing them in your diet. The American Dietetics Association recommends 50 percent of your diet be carbohydrates, but this refers to mostly complex carbs such as whole fruits and vegetables, non-refined grains and foods with lots of fiber.

People with carbohydrate sensitivity, such as diabetics, pre-diabetics and those with hypoglycemia, have to be more careful about the types and amounts of carbs they eat but still must include them in the diet. A diabetic who eats too many simple sugars will raise the blood glucose levels too fast to allow for his insulin to handle it, and a hypoglycemic eating those same foods will overproduce insulin, causing that person to drop the blood glucose too quickly. However, eating complex carbs allows for a gradual increase in blood levels and makes these foods acceptable.

There is no question that you can lose weight on a high-protein diet. Protein does not absorb water. And the higher fat content naturally included in a high-protein diet not only makes it taste great but can also be broken down and used as fuel in a process called ketosis. However, metabolism of these nutrients for fuel is more difficult for your body and causes stress on many of your internal organs. Additionally, without the fiber content of plant foods, you have a greater chance of being constipated, not to mention being deprived of those necessary B vitamins.

As for fat, at more than twice the calories per gram as a carbohydrate, it’s not a very good choice for body fuel! And while you can take vitamins in pill form, they still lack the complementary micronutrients found in a whole food. So while a high protein diet is probably not risky for short periods, and helps motivate some people to keep losing weight by showing fast initial results, it should never become a lifelong diet plan.

During childhood especially, a menu that is low in carbohydrates is just not acceptable. Children’s bodies go through periods of rapid growth where a ready source of glucose is critical. Limiting carbs in a child’s diet stresses body systems that are still maturing and deprives them of the vitamins and minerals required for optimum growth. But a diet high in simple carbohydrates, such as sweets, “junk” foods and non-fruit drinks, is not recommended for a healthy diet. Children will naturally go to the junk if it is available, so encourage snacks of whole fruits, raw vegetables and wholegrain breads and crackers. And keep the junk out of the house!

Save the cookies and candy as special treats for special holidays only, and encourage your child’s teachers to develop a policy of nutritious treats for school celebrations. Beginning early with the determination to increase complex carbohydrates in your family’s diet will pay off in children who have good weight control and better school performance.

Susan M. Leisner RD, IBCLC, RLC Nutritionist & Lactation Consultant