High-fructose corn syrup is the principal sweetening agent in most high-sugar soft drinks. Fructose provides the sweet taste in fruits. In sedentary people, it is linked to an increased risk of the metabolic syndrome (abdominal obesity, abnormal blood fats, high blood pressure, poor blood sugar regulation, inflammation and blood-clotting abnormalities). People consume about 300 more calories per day more than they did 30 years ago, largely because of an increased intake of fructose. A report published in Current Sports Medicine Reports, stated that a high fructose intake was beneficial for athletes. Fructose stimulates the digestion and promotes carbohydrate used during exercise, which are important for optimal performance. Intense training involves high energy expenditure, which protects athletes from the negative effects of fructose experienced by sedentary people.
Over consumption of high sugar soft drinks may cause obesity, insulin resistance and high blood pressure. A study from the Louisiana State University Health Science Centre found that overweight people who drank one less high sugar beverage per day during an 18 month period showed a drop in systolic and diastolic pressure of nearly 2mmHg. Researchers speculated that cutting out two drinks per day might have an even greater effect. Scientists disagree on the negative health effects of consuming high sugar beverages.