There's More to Carbs Than Meets the Eye
With the abundance of conflicting dietary advice about carbohydrates circulating the Internet it is no wonder more and more people are confused about carbs. Recently carbohydrates have been blamed for a number of ailments such as brain fog, fatigue, overweight/obesity, and high cholesterol just to name a few. The truth is, carbohydrates are delicious! Just kidding……sort of. Carbohydrates are one of our main sources of energy, and they provide many important nutrients for us, as well as the inhabitants of our gut (aka our microbiome). Carbohydrates are a complex macronutrient, and when simply labeled as “good” or “bad,” people are left wondering what to eat to promote or maintain their health. As a registered dietitian, and someone that has studied metabolism, I would like to clear up some of the confusion around carbs. Lets start with a brief introduction of what carbohydrates are.
What are carbohydrates?
Carbohydrates are one of the three macronutrients we need in our diet. (Carbohydrates, Fat and Protein). Each of these provide essential nutrients to our bodies. Carbs are plant foods that are made up of various amounts and arrangements of Carbon, Oxygen and Hydrogen. After we eat carbs our body digests them and they are ultimately turned into glucose, the main source of energy for our bodies. In addition to providing us with energy, carbohydrate foods provide us with a variety of vitamins, minerals, fiber and phytonutrients. Some phytonutrient benefits include anti-inflammatory properties, immune health support, anti-cancer, anti-microbial and protection of cellular integrity. This all sounds amazing right? So what could be bad about carbs?
Not all carbs are created equal.
There are two main types of carbohydrates, simple and complex. One of the main differences in the two is the speed, or rate, at which your body digests the food and then in turn how rapidly glucose enters your blood stream. Simple carbs are digested quickly, so we can think of them as fast carbs, because glucose enters your blood stream quickly. Complex carbs can be thought of as slow carbs, because the glucose enters your blood stream slower. The rate at which a food impacts your blood glucose is measured and is called the Glycemic Index (GI) of the food. Slow carbs have a low GI, while Fast carbs have a high GI.
Slow carbohydrates are digested slowly, resulting in a gradual rise in blood sugar. This gradual rise is desirable because it keeps our blood sugar more stable, and provides us with a steady, more sustained supply of energy. Fiber is a main contributor to the slower rate of digestion, which also helps us feel fuller longer and aids weight loss. Fiber is also the food for our microbiome, which keeps the microbes happy and can keep us happy too! (Did you know about 90% of our serotonin is produced in the gut and our microbiome influences that production!) Slow or complex carb foods include things like non-starchy vegetables, lentils, whole grains such as barley, rolled or steel cut oatmeal, most fruits and some pasta. I recommend limiting added sugars, choosing minimally processed foods, and nutrient dense, carbs with fiber.
Rapidly digested carbs, or fast carbs, are the carbohydrate foods that are digested quickly and cause a rapid increase in blood sugar (glucose). You want to limit the number of simple or fast carbs in your diet. When you do have simple carbs, be sure they are appropriately portioned and part of a balanced meal. These are foods such as white breads, cereals, instant oats, white potatoes, short-grain white rice and baked goods. Added sugars, including sugary beverages should really be limited. (I did not say avoided at all costs, otherwise you are doomed.) Enjoying a treat here and there is normal, just make sure you are enjoying it mindfully.
So why is a rapid rise in blood sugar a problem?
A rapid flux of glucose into the blood stream triggers a large release of insulin to take care of the glucose or sugar in your blood. This signals glucose uptake by muscles, synthesis of glycogen (how we store glucose in the liver), and synthesis of fat. It takes about two hours after a meal for the absorption process to be complete, and the effects of insulin continue beyond that, causing a drop in blood sugar. Low blood sugar can cause mood changes, fatigue and cravings for more sugar! We have all heard of a sugar crash, or experienced a “hangry” individual. This is because people get tired and cranky when their blood sugar is low, and they crave more carbs to pick it up again. Spikes in blood sugar, followed by a crash can lead to a viscous cycle of ups and downs in blood sugar, and can over work your pancreas (the organ busy secreting insulin to take care of the excess glucose). Furthermore, the body reacts to a state of low blood sugar by releasing hormones that signal the release of fat from our cells. Too much of this can contribute to elevated triglyceride levels, and we do not want that.
Sample Carbohydrate foods with varying Glycemic Index:
· Leafy Greens
· Minimally processed grains
· Pasta/ Holista Spaghetti
· Cream of wheat
· Mini Wheats
· Pita Bread
· Quick Cook Oats
· Whole Wheat Bread
· White bread
· White rice
· Most Crackers
In addition to the type of carbohydrate you choose, the quantity is important as well. Making sure to have appropriate portion sizes will help keep your blood sugar, and energy levels stable throughout the day, avoiding any sluggishness after a meal. Portion sizes are important for all macronutrients. Whether you are over eating protein, fat or carb, the excess your body does not need will be stored as fat. Since I am focusing on Carbs today, I would like to give you some examples of portion sizes. Please note this is a general guide based on the DASH diet. Every person has unique dietary needs, and should consult a qualified health care provider, or dietitian nutritionist for their personalized recommendations of total servings per day.
Balance, the key to life (and a healthy diet).
Lastly, it is important to note, mixed meals and snacks are recommended. When I say mixed, I mean a mix of food groups on your plate, (Fruit – Vegetable – Grains – Protein – Dairy/Dairy Alternative – Healthy Fat). Balance is not only for Yoga, it is essential for a healthy diet. Be sure to balance your plate by pairing your carbohydrates with lean proteins and healthy fats, as this will help slow digestion, and regulate energy levels as well.
*Note: Protein and fat do not contain fiber, which is why it is important to make sure you are eating your carbs!