A recent paper used network meta-analysis techniques to evaluate the effects of replacing dietary sugar in a total of 38 RCTs, with over 1300 total subjects. All studies included nutrition interventions at least 1 week long, in which dietary sugar was swapped out by some other carbohydrate with equal calories. They looked at a long list of metabolic outcomes, including LDL cholesterol, triglycerides (TG), a measure of insulin resistance (HOMA-IR), and more.
Results indicated that replacing sucrose with starch reduced LDL and fasting glucose, and replacing fructose with starch also reduced LDL. Replacing fructose with glucose reduced HOMA-IR and uric acid. No effects were observed for TG, HbA1c, CRP, ALT, or AST.
The bottom line: While this seems like a clear-cut call to cut sugar from your diet, there’s a lot more to the story. A recent study found that super high fructose intake (150g/day for 8 weeks) had no adverse effects on the metabolic parameters measured in young, healthy subjects with an average BMI of 22. As long as you’re lean and/or physically active, and eating an appropriate amount of overall carbohydrates and calories, you probably don’t have to lose much sleep over your sugar intake. However, if blood cholesterol and glucose numbers are a concern of yours, removing some of the added sugars from your diet might not be a bad idea. But be sure to cut the extraneous added sugars before you even think about reducing your fruit intake.