We’re back with another post about essential nutrients.  This time we’ll discuss the macronutrient, carbohydrates.  Previously we explained basic nutrition information and dove into the macronutrient, protein.  Carbohydrates, or carbs, have gotten a bad rap in recent years, with many diets focusing on low-carb choices and foods marketed in the same vein.  It’s time to demystify carbs and explain what they are, what your body uses them for, and current recommendations on carbohydrate consumption.

Carbohydrates:  What’s with the bad press?

In 1999 60% of US adults age 20 and older were considered overweight or obese.  This increase coincided with several trends including larger portion sizes, greater consumption of high-fat foods, widespread availability of good-tasting, low-cost, high-calorie foods, and decreased physical activity at work and home.  People began to become more and more preoccupied with dieting, spending upwards of $33 billion a year on weight-loss products, programs, and pills.  Weight loss can only happen if the calories expended are greater than the calories consumed.  People can experience initial rapid weight loss from low-carb diets from both the calorie deficit that accompanies removing or decreasing intake of an entire food group and the loss of water and electrolytes that results from the decline in insulin, the hormone used to transport glucose.  Additionally, with the absence of consumed carbohydrates, a breakdown of glycogen (or the body’s stored supply of carbohydrates) occurs, leading to additional water loss.  This initial more rapid weight loss helped these types of diets to gain popularity.  Who doesn’t like to see quick results?  In addition to the increase in overweight and obese individuals, rates of type 2 diabetes have also risen.  Diabetes is a group of diseases that affect how your body uses glucose, a type of sugar.  Individuals diagnosed with any type of diabetes should be working with a medical provider to determine the appropriate amounts and types of carbohydrates for their diet.  In the wake of these trends, confusion has ensued about what a carbohydrate is and how much, and what types to consume.

What are Carbohydrates

Most simply put, carbohydrates are sugar molecules that can be classified as simple or complex depending on their molecular structure.  We often think of sugar as the granular white stuff that we use to sweeten foods, but in fact, sugars encompass far more than that.  For example, glucose, our body’s preferred source of energy is a type of sugar.  So too, are lactose and fructose.  These are all considered simple carbohydrates.  Complex carbohydrates, which include starches and fiber are made of lots of simple sugars strung together.  Carbohydrates can be found in fruit, vegetables, grains, dairy products, legumes, beans, and lentils as well as some not-as-healthy options like sweets, chips, sodas, juices, and sports drinks.  Generally, meats, fish, poultry, nuts, and oils contain trace to no amount of carbohydrates.

Healthy Carbohydrates

Load your plate with fiber-rich vegetables, particularly from fresh or frozen sources.  Fresh and frozen whole fruits and vegetables often contain fiber, water, and bulk which helps you to feel fuller with fewer calories.  Fruit juices and dried fruits are often higher in calories for much smaller portions, so limit your intake of these carbohydrates and opt for the fresh alternative when possible.  Whole grains are better sources of fiber and important nutrients such as the B vitamin group.  When grains are refined, such as with white flour products and pasta, some of the nutrients and fiber are stripped out of the grain, making refined carbohydrates the less healthy option.  Remember, low-fat dairy can also contain carbohydrates and be a great source of protein, vitamin D, potassium, calcium, and other vitamins and minerals.  Be careful of added sugars though, which are often used to sweeten products like low-fat yogurt.  Beans, peas, and lentils are one of the most versatile and nutrient-dense foods.  They are low in fat while being high in folate, potassium, iron, magnesium, and fiber.  In addition, they’re a great substitute for meat as a source of protein.  Small amounts of added sugars in cookies, pastries, and other sweets are fine for special occasions but should be limited.  They are high in calories and typically have no other nutritional value.  Carbohydrate consumption should be focused on fresh vegetables and fruits along with whole grains.

What Carbohydrates do in the Body

  • Provide energy as the main and preferred fuel source for your body.
  • Protect against disease.
    • Studies suggest fiber may help to lower your risk of heart disease and stroke.  Additionally, fiber may protect against obesity, colon and rectal cancer, and type 2 diabetes.  Fiber helps to support the beneficial bacteria that make up part of your gut flora.  These beneficial bacteria help to protect against the disease-causing bacteria that can take up residence in the absence of the beneficial bacteria.
  • Weight control.
    • Bulk and fiber contained in healthy carbohydrates help you to feel full on fewer calories.  Few studies have actually shown that a diet rich in healthy carbs leads to weight gain or obesity.

Signs of Too Little Carbohydrates

It is rare that Americans are not eating enough carbohydrates as a whole.  However, most Americans don’t get enough healthy carbohydrates, particularly fiber.  Diets low in fiber can result in constipation, hemorrhoids, and small pouches in your colon, also known as diverticular disease.  Additionally, soluble fiber may help to lower total blood cholesterol levels.  The best sources of fiber include whole-grain products, fruits, vegetables, beans, nuts, and seeds.  In addition to constipation, individuals that have started a “low-carb” diet or drastically decrease their carb intake may experience headaches and muscle cramps.  Studies are currently underway to determine the long-term effect of carb restriction.  It has been suggested that replacing your carbohydrate intake with large amounts of fat and protein from animal sources, as is often done when going on a “low-carb” diet, may increase your risk of heart disease and certain cancers.

Carbohydrates Recommendations for Older Adults

The U.S. Department of Agriculture and the U.S. Department of Health and Human Services publishes dietary guidelines every 5 years based on recent scientific reviews of the current evidence on health topics and nutrition for every stage of life.  For carbohydrates, the MyPlate recommendations are broken into three categories, grains, fruits, and vegetables.  The most recent recommendations from the 2020-2025 guidelines for men and women ages 60 and over are listed below.  Notice the largest portion of your daily carbohydrate intake should come from foods classified as vegetables.

Below are some tables of serving size equivalents that will help you to determine your daily meal plan.  Keep in mind that fruits and vegetables that contain a high concentration of water and are not calorie dense may have larger serving size equivalents.  For example, green leaf lettuce has a two-cup chopped fresh serving size for a one-cup serving size equivalent.  These types of carbohydrates are great to load up on to fill you up while not being calorie-dense.

Carbohydrates – What to Remember

  • The best sources for any macro or micronutrients are always derived from whole foods, not supplements.  Talk with your doctor before beginning any new supplements which could include – vitamins, shakes or powders, fiber supplements, and items classified as medical foods.
  • Obtain the majority of your carbohydrates from foods classified as vegetables.
  • Most American diets are low in fiber.  Fiber, a complex carbohydrate, is extremely important in your overall health.  The best sources of fiber include whole-grain products, fruits, vegetables, beans, nuts, and seeds.  
  • Recommendations for carbohydrate intake are based on studies of healthy individuals.  People who suffer from medical conditions, particularly diabetes, should always discuss their target daily carbohydrate intake and best carbohydrate sources with a registered dietician and their medical provider.
  • Next Up:  Fats

Resources

Carbohydrates | MedlinePlus.gov (17 January, 2022).

Carbohydrates aren’t bad, but some may be healthier than others.  See why carbs are important for your health and learn which ones to choose. | MayoClinic.org (22 March, 2022)

Fruits | MyPlate.gov (2020).

Grains | MyPlate.gov (2020).

Low Carbohydrate Diet | ncbi.nlm.nih.gov (11 July, 2022).

Low-carb diet:  Can it help you lose weight? | MayoClinic.org (18 November, 2020).

McGuire, Michelle, et al. “Carbohydrates.” Nutritional Sciences, Fourth ed., Cengage Learning, Boston, MA, 2016, pp. 145-151.

Physician’s guide to popular low-carbohydrate weight-loss diets | ccjm.org (9 September 2021).

Vegetables | MyPlate.gov (2020).

By Gretchen Stevenson RN, BSN | October, 2022