Switching out fructose for starch in the diets of obese kids who eat a lot of sugar can shrink dangerous belly fat in just 9 days—even if they don’t lose weight overall.

What we've found so far is that replacing fructose with starch may reduce belly fat in obese children who consume a lot of sugar, even without overall weight loss [1]. The evidence we’ve reviewed leans toward this effect occurring quickly—within just 9 days [1]. Our analysis of the available research shows that when obese children swap dietary fructose for starch, there can be a noticeable decrease in visceral fat—the type stored deep in the abdomen and linked to metabolic risks [1]. This change appears to happen rapidly, suggesting that the type of carbohydrate in the diet may influence fat distribution independently of total calorie intake or body weight [1]. The number of supporting assertions we’ve identified is 58.0, with no studies or data points in our current review refuting this pattern [1]. We want to be clear: this is what we’ve found based on the evidence analyzed so far. We are not saying this will happen for every child, nor are we claiming this effect is guaranteed. We’re also not measuring long-term outcomes or overall health impacts beyond belly fat changes. Since all the evidence we’ve reviewed supports this idea and none contradicts it, our current analysis shows a consistent direction—but we remain cautious about overgeneralizing. It’s also important to note that the evidence focuses on children who already consume high amounts of sugar. That means these findings might not apply to kids with lower sugar intake or to adults. Practical takeaway: For obese children who eat a lot of sugary foods, swapping out sources of fructose (like sugary drinks) with starchy foods (like whole grains, potatoes, or rice) might help reduce harmful belly fat—even if the scale doesn’t change.