Complex, Simple, and Refined Carbohydrates

Dietary fiber food still life
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A healthy diet is essential for managing diabetes and losing weight. For certain food groups, particularly carbohydrates, making smart choices can be a confusing task. We are told to avoid simple and refined carbs, and to choose complex ones instead, but what does that all mean?

What Foods Contain Carbohydrates? 

Foods that contain carbohydrates include starches such as grains and starchy vegetables, fruit, milk/yogurt, snack foods, and sweets. Carbohydrates are the macronutrient that affect blood sugars the most. These types of food provide the body with energy while adding flavor, fiber, and texture to foods. 

What Do Carbohydrates Do and Why Do You Need Them? 

When eaten, carbohydrate-rich foods are metabolized and broken down into sugar or glucose. Glucose is the body's primary source of fuel or energy, but when you have prediabetes or diabetes your body does not handle sugar properly. Instead of sugar being taken to the cells to use as fuel, it remains in the blood. Excess or high sugar in the blood can eventually cause problems including heart disease, kidney disease, nerve damage, and stroke. Eating a healthy, balanced, high fiber, carbohydrate controlled diet can help to control your mood, reduce blood sugars, lose weight, and increase energy levels. Excess carbohydrate intake can cause weight gain because glucose that is not used as energy or stored for later use in the muscle or liver is stored as fat in adipose tissue.

What Types of Carbohydrates Should you Eat and Avoid? 

When choosing carbohydrates, it's best to choose complex carbohydrates that are rich in fiber and low in sugar. Simply stated, complex carbohydrates are defined as polysaccharides, which means that they contain at least three glucose molecules. Foods that fall into this category are starches, such as legumes, grains, peas, and potatoes. Dietary fiber is also considered to be a starch and is found in non-starchy vegetables and whole grains.

Simple carbohydrates are those foods that contain only one or two sugar molecules, they are referred to as monosaccharides and disaccharides. These foods include things like milk, fruit, juice, table sugar, and syrup. Some simple carbohydrates are healthy, such as fruit, and low-fat/non-fat milk. These foods can also contain protein, calcium, vitamins, minerals, antioxidants and fiber, which can boost nutrition and slow down how quickly blood sugars rise. Although they are healthy, they should be portion controlled. Other simple carbohydrates such as syrup, juice, soda, table sugar, etc contain little fiber and no real nutritional value—which can cause blood sugar spikes, cravings, and weight gain. These types of foods should be avoided altogether or eaten very sparingly.

Refined carbohydrates, such as white bread and white pasta, are starches that have been processed to remove the bran and germ of the grain, stripping them of fiber, vitamins, minerals and antioxidants. These foods can also cause big blood sugar spikes and yield little to no nutritional value. Instead of choosing refined grains, it is better to choose whole grains. In fact, research has shown that choosing whole grains instead of refined grains can reduce the risk of heart disease, decrease blood pressure and aid in weight loss. The fiber found in whole grains slows down the speed at which blood sugars rise. Whole grains also contain more vitamins, minerals, and antioxidants.

So Where Do I Start? 

Avoid these types of carbohydrates:

  • Beverages: Juice (even 100% fruit juice), soda, sweetened iced tea, lemonade, Gatorade, Vitamin water, sweetened coffee drinks, flavored milk 
  • Starches: White breads: rolls, bagels, hero bread, Italian bread, multi-grain bread (this is not necessarily a whole grain), white pasta, white rice, muffins, croissants, scones, sweetened cereals 
  • Snack foods: white crackers, chips, pretzels, sweetened dried fruit, yogurt covered snacks, cookies, cake, ice cream, candy bars, cereal bars
  • Condiments and added sugars: Syrup, sugar, brown sugar, sugar in the raw, honey, agave, molasses, corn syrup, fructose, high fructose corn syrup, sucrose, dextrose, maltose, fruit juice concentrates

Choose these carbohydrates instead:

  • Beverages with zero carbohydrates: water (add lemon or lime for added flavor), seltzer, unsweetened iced tea, herbal tea, coffee, diet drinks 
  • Beverages low in carbohydrates: almond milk (plain), soy milk (plain)
  • Dairy: Low-fat and non-fat milk, Low-fat or non-fat Greek yogurt, low-fat kefir, low-fat cottage cheese 
  • Starches: Legumes (beans), any type, preferably dry, but if canned be sure to rinse, sweet potatoes, squash, pumpkin, peas, corn, grains: 100% whole grains are best choices (oatmeal, quinoa, barley, etc), non-starchy vegetables (aim to make 1/2 your plate non-starchy vegetables)
  • Snacks and other foods: air-popped popcorn, whole grain crackers, whole grain cereals

Ask your registered dietitian or certified diabetes educator how many carbohydrates you should be eating per meal for weight and blood sugar control.

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