A new study challenges the idea that less sugar always means healthier. Researchers discovered that adults with prediabetes who ate one mango every day for six months had better blood sugar control, improved insulin sensitivity, and lower body fat than those who ate a low-sugar granola bar daily. The trial, published in Foods, is the first long-term study to show clear benefits of mangoes in people with prediabetes.

Even though mangoes contain about 32 grams of natural sugar — nearly triple the granola bar tested — their nutrients appear to make the difference. Mangoes are rich in fiber, vitamins, and antioxidants, which help the body process sugar more effectively. In contrast, low-sugar processed snacks often lack these protective compounds and may even raise diabetes risk despite the smaller sugar count.

The findings suggest that looking only at sugar grams doesn’t tell the whole story. Whole fruits, even those higher in natural sugar, can support health and may play a role in preventing diabetes. For the nearly 100 million U.S. adults with prediabetes, the takeaway is simple: food quality matters more than the number on the label.