In kids who are overweight and eat a lot of sugar, swapping out fructose (a type of sugar) for starchy foods — without changing how many calories they eat — can cut liver fat in half in less than two weeks, even if they don’t lose weight.

What we've found so far is that replacing fructose with starch may reduce liver fat in obese Latino and African American children, even without cutting calories. The evidence we’ve reviewed leans strongly in this direction. Our analysis of the available research shows that in children who are overweight and consume high amounts of sugar, swapping fructose for starchy foods can lead to a significant drop in liver fat—about half—in less than two weeks [1]. This change happened even though the total number of calories stayed the same and the children didn’t lose weight [1]. The data we examined includes 58.0 supporting assertions and no studies that refute this effect [1]. We don’t yet know if this effect applies equally to all children or only to specific groups, since the evidence focuses on overweight Latino and African American children. Also, we can’t say how long the improvement lasts or whether it leads to better long-term health, because the studies we’ve reviewed looked only at short-term changes. It’s important to note that we’re not saying fructose “causes” high liver fat or that starch “fixes” it. We’re reporting what the current data shows: when fructose is replaced with starch in the diet, liver fat tends to go down quickly in this group of children. Our current analysis suggests that the type of carbohydrate may matter for liver health, not just the number of calories. But we’re still building our understanding—this is one piece of a larger picture. Practical takeaway: For overweight children who eat a lot of sugary foods, swapping out sources of fructose (like soda and sweetened juices) for starchy foods (like whole grains, potatoes, or rice) might help lower liver fat quickly—even without cutting calories or losing weight.