Even though refined sugar adds "junk calories" to a sports diet, you need not eat a sugar-free diet to have a good diet. A fit and healthy person's menu can accommodate 10 percent of calories from refined sugar (World Health Organization's guidelines).
Yet, if you frequently consume sports drinks, gels, and sports candies—as well as other sweets—you can easily consume more than 250 to 350 calories (10 percent of calories) from refined sugar. Please don't displace too many fruits, veggies and whole grains with empty calories from sugar.
More: Avoid Junk Fitness Food
High Fructose Corn Syrup
High fructose corn syrup (HFCS), also deemed evil and fattening, is less evil and less fattening than portrayed by the media (See source 1). Ninety percent of 567 media reports on HFCS since 2004 replaced science with opinion and were biased to the erroneous (See source 2).
HFCS is a double molecule comprised of 45 percent glucose, 55 percent fructose—the same as honey and similar to white sugar (50 percent glucose, 50 percent fructose). The negative hype about HFCS applies primarily to overweight folks 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? No.
Are Carbs Fattening?
Despite popular belief, carbohydrates are not inherently fattening. Excess calories are fattening. Excess calories of carbs (bread, bagels, pasta) are actually less fattening than excess calories of fat (butter, salad oil, cheese). That's because storing excess calories of sugar as body fat requires more energy than storing excess calories of dietary fat as body fat. This means, if you're destined to be gluttonous and want to suffer the least weight gain, indulge in (high carb) frozen yogurt instead of (high fat) ice cream.