Nancy Clark by Nancy Clark

Carbohydrates: Why are They So Confusing?

Carbohydrates can be a source of confusion for athletes and fitness enthusiasts alike, many of whom believe they should avoid pasta, bagels, juice, bananas, sugar... the list goes on. In reality, people who are physically inactive whose bodies do not readily metabolize carbohydrates may need to take a different approach to consuming carbohydrates compared to regular exercisers and athletes. Here’s some information to help resolve carbohydrate confusion.

What do you actually mean when you say “carbs”?

  • Carbohydrates include both sugars and starches; they are biochemically similar. For example, an unripe banana (or any fruit) is starchy. As it ripens, it becomes sweeter; the starch converts into sugar. In comparison, peas (and other vegetables) are sweet when young and their sugar converts into starch as they mature.
  • All forms of sugar and starch digest into the simple sugar glucose. Glucose travels in the blood and, with the help of insulin, is taken up for fuel by the muscles to fuel your workouts. Fit bodies handle carbohydrates better than unfit bodies.

Are carbs bad for you?

  • Regarding health, some carbs are better for you than others because some offer more nutrients than others. Even though refined sugar adds “empty calories” to a sports diet, you need not eat a sugar-free diet to have a healthy diet. A physically fit, healthy person’s menu can accommodate 10% of calories from refined sugar (World Health Organization’s guidelines). Yet, if you frequently consume sweets plus sports drinks, gels and sports candies, you can easily consume more than 250 to 350 calories (10% of calories) from refined sugar.
  • The fear-mongering terms of unhealthy, toxic and poisonous that surround conversations regarding carbohydrate are simply unscientific. People who lack knowledge about physiology accept this disease-mongering, anti-sugar rhetoric. But the fact is no one food is healthy or unhealthy.

Are carbs fattening?

  • Despite popular belief, carbohydrates are not inherently fattening. Excess calories are fattening.

What about high-fructose corn syrup?

  • High-fructose corn syrup (HFCS) is less evil than is often portrayed by the media. HFCS is a double molecule comprised of 45% glucose, 55% fructose—the same as honey and similar to white sugar (50% glucose, 50% fructose).
  • The negative hype about HFCS applies primarily to people who consume excessive calories of sweets, soda, candies and processed foods sweetened with HFCS. While no one needs excessive, lack-luster calories that could be better spent on nutrient-rich fruits, veggie and whole grains, does an athlete really need to fret about a few calories of HFCS in ketchup?

What about sugar “crashes”?

  • The most common reason for “sugar crashes” (hypoglycemia) among athletes relates to running out of fuel. The shakiness and sweats are because the athlete did not eat enough food to maintain normal blood glucose levels and the brain is now demanding sugar. One marathoner, who thought the 100-calorie gel he consumed at mile 16 caused him to “crash,” more likely needed 200 to 300 calories to meet his energy needs.
  • A sharp rise in blood sugar that may occur after eating sugary foods is not pathological, and has more to do with the efficiency of the muscles and liver in their ability to take up the sugar. Exercise enhances the transport of sugar from your blood into your muscles with far less insulin than needed by the body of a person who is physically inactive.


For physically active, fit people who are at lower risk for heart disease, diabetes and obesity, sugar and carbs are not toxic, and may be a helpful way to enhance athletic performance. The one-size-diet does not fit all.

No one is suggesting that you or your clients should eat more sugar, but rather understand that athletes and people who are regularly physically active can embrace a way of eating that includes an appropriate balance of carbohydrate (sugars and starches) in each meal. Strive for a healthy eating pattern that includes 85-90% quality foods and 10-15% whatever. Some days, whatever might be an apple; other days, it might be a slice of apple pie.

Want to help your clients make healthier, long-lasting food choices? Become an ACE Fitness Nutrition Specialist


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