OH NO, CARBS! Low-carb, no-carb, or high-carb diet – which one should I follow? Well, there are so many misconceptions about carbs and their contribution to weight loss, weight maintenance, and weight gain. Those diets have no middle ground (and limited flexibility), so I want to clarify the basics and the importance of carbs in our diet.
Carbohydrates are part of the three macronutrients: protein, fats, and carbs. We need all three in varying degrees, depending on where we are emotionally, physically, and psychologically in our lives.
Dietary carbohydrates include:
- Monosaccharides: simple sugars
- Disaccharides: sugars composed of pairs of single sugars
- Oligosaccharides: large molecules found in fruits and vegetables
- Polysaccharides: large molecules composed of monosaccharides
Monosaccharides (one molecule) include glucose, fructose, and galactose
- Glucose: referred to as blood sugar, it is the essential energy source for our body.
- Fructose: this is the sweetest of the sugars, naturally occurring in fruit and honey, and added to many sodas and processed foods.
- Galactose: does not occur in many foods, but is part of the disaccharide lactose, which is found in milk.
Disaccharides: (two molecules) include maltose, sucrose, and lactose
- Maltose: consists of two glucose molecules, mostly found in malt beverages such as beer and malt liquor.
- Sucrose: consists of glucose and fructose, mostly found in cane sugar and beet sugar.
- Lactose: consists of galactose and glucose, mostly found in milk and milk products.
Oligosaccharides: (many molecules)
- Also referred to as fructooligosaccharides (FOS), mostly found in beans, peas, bran, and whole grains.
Polysaccharides: (many molecules) include starches, fiber, glycogen, amylose, and inulin.
- Glycogen: found in limited quantities in meat and not at all in plants – however, it is our body’s form of storing glucose in the liver and the muscles.
- Starches: plant cells store glucose as starch, so plants are a huge source of starch – mostly found in wheat, rice, yams, potatoes, and legumes.
- Fiber: found in vegetables, fruits, whole grains, and legumes.Dietary fibers are indigestible by the body. There are soluble fibers that dissolve in water, creating a viscous gel and are digested by bacteria in the colon. These are found in oats, barley, legumes, and citrus fruits. Soluble fibers protect against heart disease and diabetes by lowering blood cholesterol and glucose levels.Insoluble fibers do not dissolve in water and are not fermented by bacteria in the gut, but provide bulk to the stool. Insoluble fibers promote bowel movements.
HOW DO WE DIGEST CARBS?
Digestion of starch begins in the mouth with the enzyme amylase breaking down the long chains of molecules. The food reaches the stomach, and digestion of the starch comes to a halt. Once the food reaches the small intestine, the pancreatic enzymes start their work, breaking the long chains of starch molecules down to single molecules of glucose, fructose, and galactose for absorption. Glucose goes to the liver, where it is then distributed for energy. This may include storage in fat cells, using it for immediate energy, or storing it as glycogen for later use.
Your body does not digest fiber, instead, it is broken down by bacterial enzymes in your large intestine. This is a key component in digestive health as it helps reduce cholesterol, relieve constipation, and protect against heart disease.
SO HOW MANY CARBS DO WE NEED?
Interestingly, we do not need any carbs. We can survive on other sources of energy derived from fatty acids and amino acids. When we do not replenish depleted glycogen stores with carbs, our body will break down body proteins to make glucose for the brain and other cells. When we do not replenish depleted glycogen stores with carbs, our body can also use fatty acids to make glucose.
If there is an abundance of carbs, our body will not break down proteins, nor will it pull from fat reserves for energy. When carbs are in abundance, fat is conserved or created. Fat reserves are created when there is an excess amount of carbs because our liver can only store the carbs as glycogen up to a limited amount, and then the rest will be stored as fat. We have an unlimited storage system for fat reserves, so the more carbs we eat in excess, our body will convert this excess into fat.
There is a happy medium to carb intake. It depends on activity level, genetics, age, stress level, disease state, and gender. We can work on this together to determine your optimal carb intake!